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Early life gut microbiota profiles linked to synbiotic formula effects: a randomized clinical trial in European infants.
Lagkouvardos, I, Intze, E, Schaubeck, M, Rooney, JP, Hecht, C, Piloquet, H, Clavel, T
The American journal of clinical nutrition. 2023;117(2):326-339
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Microbial colonisation of the intestine after birth is a central event that influences infant health with life-long consequences. Although improvement of hygienic conditions reduces infant mortality due to infections, environments with low microbial biomass counteract natural colonisation by commensal microbes. The aim of this study was to assess the effects of a synbiotic intervention formula (IF) on faecal microbiota. This study was a multicentre, randomised, controlled, double-blind intervention trial which enrolled 540 infants. Infants whose parents had chosen not to breastfeed or were not able to breastfeed prior to study inclusion were allocated randomly to 1 of 2 formula groups (n = 230 control formula, n = 230 IF). The infants in the breastfed reference group (n = 80) were mainly fed human milk. Results showed that synbiotic intervention influenced the gut microbiota and milieu parameters during early life to resemble some major characteristics found in breastfed infants (higher relative abundances of bifidobacteria, lower richness, lower faecal pH and butyrate concentrations), and effects depended on the ecosystem profile of the infants. Authors conclude that specific randomised, controlled studies that focus on infants born by Caesarean section and how early nutrition can support the beneficial development of their microbiota are needed.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Infant gut colonisation differs in vaginal versus cesarean section deliveries and between breastfed and infant formula practices.
- Both enriched strain-specific probiotic and standard infant formula were shown to have a marked effect on microbiota colonisation in infants at age 4 months.
- By the age of 2 years, however, there is no significant difference between breastfed and formula fed infants.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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X
B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
This randomised controlled intervention study compared gut health parameters with the use of a synbiotic pre- and probiotic strain enriched infant formula with human milk and standard formula at three intervals over a period of 2 years.
Methods
This was a double-blinded controlled study of 540 infants from France and Belgium. Participants were randomly allocated to 2 formula groups (n = 230 Control Formula (CF), n = 230 Intervention Formula (IF)) and the breastfed reference group (n = 80) as well as delivery mode (Cesarean and vaginal delivery). The synbiotic IF was a standard infant formula enriched with prebiotic GOS (0.02 g/g) and the probiotic strain L. fermentum CECT5716 (at least 1.0 × 106 cfu/g).
Stool analysis was conducted at three time intervals, 4, 12, and 24 months (infant age). Biomarkers included short chain fatty acids, pH, secretory IgA, calprotectin, and various bacterial phyla via microbiota analysis.
Results
- At 4 months, the IF group tested higher for Bifidobacterium spp., and Lactobacillaceae and lower occurrence of Blautia spp., as well as Ruminoccocus gnavus and relatives compared to CF. They also had lower fecal pH and butyrate levels
- Both the formula cohorts had lower SigA and more basic pH values than the human milk cohort, as well as higher prevalence of anaerobes belonging to the bacterial genera Akkermansia, Collinsella, and Faecalibacterium.
- By age 24 months, the IF cohort exhibited increased levels of Akkermansia, Escherichia-Shigella, and R.gnavus. However there were no significant differences between the formula fed and human milk cohort at this time interval.
- The differences observed at 4 months disappeared over time, except for a significantly higher relative abundance of bifidobacteria and Faecalibacterium spp. in IF infants at 12 months compared with CF infants.
Conclusion:
Although prominent differences between the cohorts were observed at 4 months, it appears that by the age of 2 years, there is little observable difference. This is most likely due to gut ecosystem maturation. The paper draws attention to the fact that changes to microbiota following treatment were more pronounced in infants who tested lower in occurrences of Bacteroides spp at age 4 months. Of note is the prevalence of cesarean birth deliveries in this cohort thereby indicating potential improved alternative feeding options when breastfeeding is not possible for these infants.
Clinical practice applications:
- Probiotic L.fermentum and prebiotic galacto-oligosaccharide enriched infant formula appears to the improve infant microbiome, when compared to that of breastfed infants.
- The most receptive infants were those born via cesarean section.
Limitations to consider:
- The sample groups were from France and Belgium, with no indication as to culture, socio-economic, or sex distribution.
- The two infant formula groups were n=230 each with only 80 infants in the breastfed reference group.
- There was no indication of maternal diet practices pre-, during, and post- pregnancy.
- Stool samples were not collected from the infants at baseline visit prior to formula intervention.
Considerations for future research:
- Future studies need to include more diverse cultural and socio-economic cohorts to ascertain the potential influence of parental diet in baseline infant microbiome.
- It is imperative to establish what role solid food choices, generally introduced at 6 months, might have on gut ecosystem maturation.
- It would be useful to have a larger cesarean section birth cohort to compare to vaginal deliveries for more definitive results.
Abstract
BACKGROUND Microbial colonization of the gastrointestinal tract after birth is an essential event that influences infant health with life-long consequences. Therefore, it is important to investigate strategies to positively modulate colonization in early life. OBJECTIVES This randomized, controlled intervention study included 540 infants to investigate the effects of a synbiotic intervention formula (IF) containing Limosilactobacillus fermentum CECT5716 and galacto-oligosaccharides on the fecal microbiome. METHODS The fecal microbiota from infants was analyzed by 16S rRNA amplicon sequencing at 4, 12, and 24 months of age. Metabolites (e.g., short-chain fatty acids) and other milieu parameters (e.g., pH, humidity, and IgA) were also measured in stool samples. RESULTS Microbiota profiles changed with age, with major differences in diversity and composition. Significant effects of the synbiotic IF compared with control formula (CF) were visible at month 4, including higher occurrence of Bifidobacterium spp. and Lactobacillaceae and lower occurrence of Blautia spp., as well as Ruminoccocus gnavus and relatives. This was accompanied by lower fecal pH and concentrations of butyrate. After de novo clustering at 4 months of age, overall phylogenetic profiles of the infants receiving IF were closer to reference profiles of those fed with human milk than infants fed CF. The changes owing to IF were associated with fecal microbiota states characterized by lower occurrence of Bacteroides compared with higher levels of Firmicutes (valid name Bacillota), Proteobacteria (valid name Pseudomonadota), and Bifidobacterium at 4 months of age. These microbiota states were linked to higher prevalence of infants born by Cesarean section. CONCLUSIONS The synbiotic intervention influenced fecal microbiota and milieu parameters at an early age depending on the overall microbiota profiles of the infants, sharing a few similarities with breastfed infants. This trial was registered at clinicaltrials.gov as NCT02221687.
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2.
Functional response to a microbial synbiotic in the gastrointestinal system of children: a randomized clinical trial.
Tierney, BT, Versalovic, J, Fasano, A, Petrosino, JF, Chumpitazi, BP, Mayer, EA, Boetes, J, Smits, G, Parkar, SG, Voreades, N, et al
Pediatric research. 2023;93(7):2005-2013
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The composition of the human gut microbiome has been identified as playing a role in regulating bowel movements in children. This includes functional constipation, which is characterised by infrequent bowel movements and associated phenotypes such as stool consistency, pain when defecating and bloating. The aim of this study was to determine the impact of a nine-strain (eight species) synbiotic (a prebiotic and defined microbial consortium) formulation (with the prebiotic comprising mixed-chain length oligosaccharides) on ameliorating constipation. This study was a multicentre, randomised, double-blind, and placebo-controlled with two parallel arms. Ninety-one healthy male/female subjects were recruited and randomly assigned to one of the two arms; treatment or placebo group. Results showed that: - compared to placebo, synbiotic use increased weekly bowel movements (WBMs) in constipated children. - there was an increased abundance of the administered probiotic species (bifidobacteria) in the treatment arm. - baseline microbial richness demonstrated potential as a predictive biomarker for response to intervention. Authors conclude that a synbiotic formulation may increase weekly WBMs in children who have low-frequency WBMs.
Abstract
BACKGROUND Oral microbial therapy has been studied as an intervention for a range of gastrointestinal disorders. Though research suggests that microbial exposure may affect the gastrointestinal system, motility, and host immunity in a pediatric population, data have been inconsistent, with most prior studies being in neither a randomized nor placebo-controlled setting. The aim of this randomized, placebo-controlled study was to evaluate the efficacy of a synbiotic on increasing weekly bowel movements (WBMs) in constipated children. METHODS Sixty-four children (3-17 years of age) were randomized to receive a synbiotic (n = 33) comprising mixed-chain length oligosaccharides and nine microbial strains, or placebo (n = 31) for 84 days. Stool microbiota was analyzed on samples collected at baseline and completion. The primary outcome was a change from baseline of WBMs in the treatment group compared to placebo. RESULTS Treatment increased (p < 0.05) the number of WBMs in children with low baseline WBMs, despite broadly distinctive baseline microbiome signatures. Sequencing revealed that low baseline microbial richness in the treatment group significantly anticipated improvements in constipation (p = 0.00074). CONCLUSIONS These findings suggest the potential for (i) multi-species-synbiotic interventions to improve digestive health in a pediatric population and (ii) bioinformatics-based methods to predict response to microbial interventions in children. IMPACT Synbiotic microbial treatment improved the number of spontaneous weekly bowel movements in children compared to placebo. Intervention induced an increased abundance of bifidobacteria in children, compared to placebo. All administered probiotic species were enriched in the gut microbiome of the intervention group compared to placebo. Baseline microbial richness demonstrated potential as a predictive biomarker for response to intervention.
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3.
Efficacy of a Synbiotic Containing Lactobacillus paracasei DKGF1 and Opuntia humifusa in Elderly Patients with Irritable Bowel Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial.
Oh, JH, Jang, YS, Kang, D, Kim, HS, Kim, EJ, Park, SY, Kim, CH, Min, YW, Chang, DK
Gut and liver. 2023;17(1):100-107
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Irritable bowel syndrome (IBS) affects 1 in 10 people globally and is a common health problem for the elderly. Recent studies have shown that changes in the gut microbiome may play an important part in IBS and there is evidence that using pre and pro biotics have positive effects on IBS. The aim of this randomized, double-blind, placebo-controlled trial was to determine the effects of a new synbiotic formulation (L. paracasei DKGF1 and prebiotics extracted from O. humifusa) on GI symptoms in elderly patients with IBS. 67 participants were randomly divided into 2 groups. For 4 weeks one group took the synbiotic and the other group took a placebo. Symptoms were recorded via questionnaires. The consumption of the synbiotic combination was associated with overall relief of IBS symptoms in elderly patients. In particular, abdominal pain and psychological well-being noticeably improved. In conclusion this synbiotic is effective and safe to use in elderly patients with global IBS symptoms.
Expert Review
Conflicts of interest:
None
Take Home Message:
- The management of IBS in elderly people is more complicated than in younger populations.
- Synbiotic formulations containing both probiotics and prebiotics have reported gastrointestinal health benefits.
- This randomized controlled trial indicated that the synbiotic containing L. paracasei DKGF1 and Optuntia humifusa extracts might be effective and safe for treating IBS symptoms in elderly patients.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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X
B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
This study involved a randomized, double-blind, placebo-controlled trial to investigate the impact of a synbiotic combination, comprising of L. paracasei DKGF1 and prebiotics extracted from Optuntia humifusa, on Irritable Bowel Syndrome (IBS) in elderly patients.
Method
Sixty-seven IBS patients (mean age: 64 years) were randomly assigned to either a synbiotic group (n=33) or a placebo group (n=34) for a 4-week intervention. The synbiotic group received a daily sachet containing one billion colony-forming units of L. paracasei DKGF1, 0.2g of O. humifusa extract and 1.59 grams of maltodextrin, while the placebo group received an identical sachet containing only maltodextrin.
During the study period
- Participants recorded the degree of symptom improvement using a Subject Global Assessment (SGA) scale.
- IBS symptoms, abdominal pain, gas, bloating, and psychological well-being were recorded using a Visual Analogue Scale (VAS).
- Stool form and consistency were assessed using a Bristol Stool Chart (BSC).
Results
The primary findings from the study were as follows:
- There was significant improvement in IBS symptoms as measured by the SGA score, in the synbiotic group versus the placebo group (+50.5% vs +23.5%, p=0.017). The synbiotic group consistently demonstrated improved response rates.
The secondary findings were as follows:
- Participants also reported an improvement in psychological well-being in the synbiotic group (from 1.3 to 1.0) compared to the placebo group (from 3.0 to 2.0) (p=0.003).
- Responders reported a significant improvement in stool form and consistency in the synbiotic group (+85.7%) compared to the placebo group (+22.2%) (p=0.04).
- Among the patients with IBS constipation, patients in the synbiotic group reported a positive response compared to the placebo group (0% and +100%, p=0.029).
- . However, there was no significant improvement among the patients with IBS diarrhoea in the synbiotic group compared to the placebo group (+33.3% and +66.6%,, p=0.52).
Conclusion:
This randomized, double-blind, placebo-controlled trial, reported that the synbiotic combination of L. paracasei DKGF1 and Optuntia humifusa, may be associated with the relief of IBS symptoms in elderly patients, particularly in terms of abdominal pain and psychological well-being.
Clinical practice applications:
- The human microbiota undergoes changes in diversity and variation with age, emphasising the importance of understanding age-specific interventions.
- Managing IBS in the elderly is challenging, and synbiotics, containing both probiotics and prebiotics, have reported gastrointestinal health benefits.
- Most clinical trials have excluded elderly patients, and there has been uncertainty about whether synbiotic use is safe for the elderly.
- This study focused exclusively on elderly patients with IBS, indicating the potential safety and effective use of a synbiotic containing L. paracasei DKGF1 and Optuntia humifusa in improving IBS symptoms.
Considerations for future research:
- Only elderly patients were included in this study, therefore further investigation is needed to explore the effects of synbiotics on participants of different age groups.
- Microbial analysis was not done in this study. It would be useful to include this in future research to gain more insight into the microbiome’s diversity in elderly patients with IBS.
- The study did not quantify food intake or variety which might have impacted the results, therefore future research needs to consider the impact diet has on the microbiome and IBS.
- Since patient reports are subjective, future research should consider involving researchers during patient-reported assessments to enhance the accuracy and reliability of the data.
Abstract
BACKGROUND/AIMS: There is increasing evidence that supplementation with pre- and probiotics appears to have positive effects on irritable bowel syndrome (IBS). The aim of this study was to determine the effects of a new synbiotic formulation on gastrointestinal symptoms in elderly patients with IBS. METHODS Sixty-seven IBS patients aged ≥60 years were randomly assigned to either a placebo group (n=34) or a synbiotic group (n=33). During a 4-week intervention, subjects used a placebo or a synbiotic containing Lactobacillus paracasei DKGF1 and extracts of Opuntia humifusa once a day. Patients were evaluated with the subject global assessment, visual analog scale, and Bristol stool chart. The primary outcome was the overall responder rate and the secondary outcome was the responder rates for abdominal symptom reduction at week 4. RESULTS Overall, responder rates were significantly higher in the synbiotic group (51.5%) than in the placebo group (23.5%) (p=0.017). Abdominal pain (58.8% vs 81.8%) and psychological well-being (26.4% vs 60.6%) were noticeably improved in the synbiotic group (p=0.038 and p=0.004, respectively). However, there were no significant differences in gas and bloating symptoms (p=0.88 and p=0.88, respectively). In patients with constipation-dominant and diarrhea-dominant IBS (n=16), the synbiotic significantly improved abdominal pain and defecation symptoms (responder rates for the placebo vs the synbiotic: 22.2% vs 85.7%, p=0.04). There were no adverse events in either group. CONCLUSIONS The results indicate that this new synbiotic supplement can potentially relieve abdominal symptoms in elderly IBS patients.
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Diet as an Optional Treatment in Adults With Inflammatory Bowel Disease: A Systematic Review of the Literature.
Jaramillo, AP, Abaza, A, Sid Idris, F, Anis, H, Vahora, I, Moparthi, KP, Al Rushaidi, MT, Muddam, M, Obajeun, OA
Cureus. 2023;15(7):e42057
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Crohn's disease (CD) and ulcerative colitis (UC) are linked with significant morbidity and higher healthcare costs. The current model of CD pathogenesis implies that environmental variables and the gut microbiota interact in those who are genetically predisposed to the condition. The aim of this study was to investigate a treatment based on the diet of IBD patients. This study was a systematic review of nine studies. Results showed that following a diet that reduces inflammation may prevent its recurrence in UC patients in clinical remission. In fact, there were significant systemic changes in the intestinal microbiota of anti-inflammatory diet patients. Authors concluded that a four-week FODMAP diet combined with professional counseling and regular follow-up will be helpful in the therapy of persistent gastrointestinal symptoms in quiescent IBD, although care should be used in the long run.
Expert Review
Conflicts of interest:
None
Take Home Message:
Whilst concise, this limited review highlights the current lack of evidence supporting stand alone dietary strategies in preventing relapse for IBD patients. At the very least an anti-inflammatory diet should ideally be implemented alongside specific medical care and counselling to minimise risk of disease relapses.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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X
B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
This systematic review evaluated the efficacy of diet as a preventative therapeutic treatment for Inflammatory Bowel Disease (IBD).
Methods
A total of 9 studies (published in the last 5 years) were chosen. The articles included 6 randomised controlled trials (RCT), one systematic literature review (SLR) and two SLR and meta-analysis. The authors used the Assessment Systematic Reviews (AMSTAR) approach and an unspecified Cochrane Risk of Bias assessment tool.
Results
(The following refers to the original RCT articles as the review article data was sparse).
- A 6-month, open-label, randomised, placebo-controlled trial of 53 adult Ulcerative Colitis (UC) patients compared response to an Anti-inflammatory Diet (AID) with Canada’s Food Guide (CFG). The outcome showed that the faecal calprotectin value (<150 µg/g at the endpoint) was significantly higher in the AID group (69.2 vs. 37.0%, p = 0.02) (Keshteli et al., 2022).
- The Specific Carbohydrate Diet (SCD) was not superior to the Mediterranean Diet (MD) in terms of achieved symptomatic remission at 6 weeks (SCD 46.5%, MD 43.5%; p = .77) (Lewis et al., 2022).
- A single-blind, 4-week trial concluded significant relief from gut symptoms was achieved when comparing a low FODMAP diet (14/27, 52% of positive patient feedback) to a control diet (4/25, 16%, p=.007) (Cox et al., 2020).
- A 7-day trial of 28 volunteers compared individualised food-based diet (CD-TREAT), with similar composition to Exclusive Enteral Nutrition (EEN) and found a change in relative abundance in faecal microbiome genera of 58 (49.3%) and 38 (32.3%) following both feeding practices respectively (Svolos et al., 2019).
- Substantial reduction in red and processed meat was not significant in reducing time to symptomatic relapse in Crohn’s Disease (CD) patients when comparing 115 high red meat consumers with 87 low red meat CD patients (p = 0.61 any relapse and p = 0.50 for moderate to severe relapse) (Aldenberg et al., 2019).
Conclusion
An anti-inflammatory diet may prolong clinical remission for UC patients. CD patients, with mild to severe symptoms, may tolerate both the MD and SCD equally well. The authors advise a low FODMAP diet for a 4-week period combined with professional counselling and regular follow-up sessions to delay flare-up episodes. However the findings were based on a very limited number of scientific material that requires extensive further assessment prior to deriving any firm conclusions.
Clinical practice applications:
- In order to delay relapse in IBD it is imperative that foods that support anti-inflammatory mechanisms are incorporated and maintained
- Whilst limited, the papers reviewed highlight potential for an initial low FODMAP diet followed by a longer term MD or SCD combined with constant monitoring
- From one study, red meat consumption did not appear to exacerbate symptoms.
Considerations for future research:
- Future studies need to include larger cohorts to ascertain the efficacy of dietary interventions as a stand alone treatment option for IBD
- Longer periods of intervention are needed to confirm dietary intervention efficacy and safety in this population.
Abstract
While the exact cause of IBD is unknown, there are a number of factors that are thought to contribute to its development, including environmental and genetic factors. While exclusive enteral nutrition (EEN) is a promising therapy for Crohn's disease (CD), it is not yet considered a first-line treatment. Additionally, the efficacy of EEN compared to corticosteroid treatment is still being investigated. EEN is suggested as a first-line therapy by which guidelines and in which age groups, as it may differ in pediatric and adult recommendations. Another finding was that dietary changes involving an increase in anti-inflammatory foods and decreased intake of foods high in inflammatory compounds are linked to a beneficial outcome both metabolically and microbiologically in patients with ulcerative colitis (UC) in remission. For relevant medical literature, we examined PubMed/Medline, the Cochrane Library, and Google Scholar as examples of medical databases. The articles were identified, evaluated, and eligibility applied, and nine publications were found. The finished articles investigated the role of several diet alternatives for patients with IBD. Some others have shown that following a normal low-fat diet may be effective in reducing the occurrence of subclinical colitis. The EEN and partial enteral nutrition (PEN) indicated no significant differences between both regimens, but both had good outcomes during active IBD. Other strict diets, such as the specific carbohydrate diet (SCD) versus the Mediterranean diet (MD), demonstrate excellent outcomes in patients with IBD. Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) dietary counseling improves gastrointestinal symptoms and quality of life in IBD patients. Based on the above, we concluded that more studies determining which component of the diet is not clear (proteins, carbs balanced) or diet types are required to establish a particular diet employed as a treatment intervention in these individuals.
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5.
The Role of Genetically Engineered Probiotics for Treatment of Inflammatory Bowel Disease: A Systematic Review.
Zhang, T, Zhang, J, Duan, L
Nutrients. 2023;15(7)
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Inflammatory bowel disease (IBD), largely classified as Crohn’s disease (CD) or ulcerative colitis (UC), is a chronic intestinal inflammatory disorder mediated by genetic, immune, microbial, and environmental factors. The aim of this study was to summarise the efficacy of different genetically modified probiotics compared to wild-type probiotics in the treatment of IBD in animal models and patients and to investigate the specific effects and main mechanisms involved. This study was a systematic review of forty-five preclinical studies and one clinical study. Results showed a protective effect of genetically modified organisms (gm) probiotics in colitis. Several protective mechanisms have been identified: reduction of the pro- to anti-inflammatory cytokine ratio in colonic tissue and plasma, modulation of the activity of oxidative stress in the colon, improvement of intestinal barrier integrity, modulation of the diversity and composition of gut microbiota, and production of favourable metabolites, including short-chain fatty acids, by beneficial bacteria. Authors concluded that gm probiotics are more effective and safer than wild-type probiotics, to facilitate clinical translation.
Expert Review
Conflicts of interest:
None
Take Home Message:
Conclusions of this review were largely based on mouse models and although treatment using probiotics is generally considered safe in humans, with only minor side-effects (flatulence), practitioners need to be aware that in an IBD population the use of GM formulations might not be completely without risk.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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X
B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
This paper summarises the efficacy of specific genetically modified (GM) probiotic formulations for Inflammatory Bowel Disease (IBD) when compared to wild type probiotics. The aim was to ascertain what specific effects and mechanisms such probiotics have on IBD symptomatology.
Methods
- A total of 46 published articles were included; 45 mouse experimental models (induced acute or chronic colitis) (n=15-130) and 1 human IBD population clinical trial (n=10)
- The effect of GM probiotics were compared to placebo and wild-type probiotics in trials including preclinical studies, randomised controlled trials and cohort studies
- Animals received probiotics via gastric gavage (105 - 4 x 1012 CFU) for 3-6 weeks
- The human placebo-uncontrolled trial lasted 7 days and patients received 10 GM capsules of L.lactis (1 x 1010 CFU) twice daily.
Results
- GM probiotics that secrete immunoregulatory cytokines such as IL-10 appear to reduce intestinal damage
- The human trial using GM L.lactis resulted in 5 patients who went into complete clinical remission (CDAI, <150) with 3 patients exhibiting a clinical response (decrease in CDAI, >70). with only minor adverse events (flatulence)
- However, human cytokines that promote intestinal barrier function and epithelial restitution were not enhanced with oral administration of probiotics
- Two studies concluded that GM L.lactis and S.boulardii, that secrete atrial natriuretic peptide, might be the most effective options in supporting colitis
- GM L.casei resulted in faster recovery from weight loss in acute colitis models
- Superoxide dismutase (SOD) producing GM L.fermentum increased SOD activity by almost eightfold compared to the wild type
- GM Lact. fermentum furthermore showed a higher survival rate and lower disease activity index (P <0·05) in colitis models
- GM L.lactis improved gut microbial composition and GM S.cerevisiae improved microbial diversity whilst reducing the Firmicutes to Bacteroides ratio
- GM E.coli significantly reduced weight loss, colon shortening plus lower disease activity and histological changes (P < 0.05).
Conclusion
Despite the heterogeneity of the trials, GM probiotics appear to play a notable part in ameliorating IBD symptomatology and disease severity when compared to wild-type probiotics. Human efficacy and potential adverse effects require more in-depth trials to ascertain safety and optimal dosages.
Clinical practice applications:
- Probiotics species used in the trials included S.thermophilus, E.coli, L.lactis, B.ovatus, S.boulardii, L.fermentum, B.longhum, L.casei, L.plantarum, and S.cerevisiae. Wild-types of some of these are already available to use in clinical practice
- Note that oral administration in the human trial showed no significant health outcome, therefore efficacy and safety need to be ascertained on an individual patient level
- Colonisation of beneficial bacteria in the gut of IBD patients might be difficult and any form of supplementation therefore needs to be closely monitored.
Considerations for future research:
- More evidence is needed to demonstrate that GM probiotic formulations result in significantly improved outcomes when compared to wild-types
- Future randomised placebo-controlled trials need to include larger cohorts to determine supplement efficacy
- Longer periods of intervention are needed to confirm efficacy, safety, and tolerance for both Crohn’s Disease and Colitis
- Optimal GM probiotic formulation, doses, and means of application need to be identified.
Abstract
BACKGROUND Many preclinical studies have demonstrated the effectiveness of genetically modified probiotics (gm probiotics) in animal models of inflammatory bowel disease (IBD). OBJECTIVE This systematic review was performed to investigate the role of gm probiotics in treating IBD and to clarify the involved mechanisms. METHODS PubMed, Web of Science, Cochrane Library, and Medline were searched from their inception to 18 September 2022 to identify preclinical and clinical studies exploring the efficacy of gm probiotics in IBD animal models or IBD patients. Two independent researchers extracted data from the included studies, and the data were pooled by the type of study; that is, preclinical or clinical. RESULTS Forty-five preclinical studies were included. In these studies, sodium dextran sulfate and trinitrobenzene sulfonic acid were used to induce colitis. Eleven probiotic species have been genetically modified to produce therapeutic substances, including IL-10, antimicrobial peptides, antioxidant enzymes, and short-chain fatty acids, with potential therapeutic properties against colitis. The results showed generally positive effects of gm probiotics in reducing disease activity and ameliorating intestinal damage in IBD models; however, the efficacy of gm probiotics compared to that of wild-type probiotics in many studies was unclear. The main mechanisms identified include modulation of the diversity and composition of the gut microbiota, production of regulatory metabolites by beneficial bacteria, reduction of the pro- to anti-inflammatory cytokine ratio in colonic tissue and plasma, modulation of oxidative stress activity in the colon, and improvement of intestinal barrier integrity. Moreover, only one clinical trial with 10 patients with Crohn's disease was included, which showed that L. lactis producing IL-10 was safe, and a decrease in disease activity was observed in these patients. CONCLUSIONS Gm probiotics have a certain efficacy in colitis models through several mechanisms. However, given the scarcity of clinical trials, it is important for researchers to pay more attention to gm probiotics that are more effective and safer than wild-type probiotics to facilitate further clinical translation.
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6.
Gut Microbiota-Derived Metabolites and Cardiovascular Disease Risk: A Systematic Review of Prospective Cohort Studies.
Sanchez-Gimenez, R, Ahmed-Khodja, W, Molina, Y, Peiró, OM, Bonet, G, Carrasquer, A, Fragkiadakis, GA, Bulló, M, Bardaji, A, Papandreou, C
Nutrients. 2022;14(13)
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Cardiovascular disease (CVD) remains a major public health issue. Identification of circulating biomarkers with prognostic value may help to both identify pathophysiological processes relevant to CVD development and improve preventive cardiovascular risk reduction efforts. The aim of this study was to identify the association of circulating levels of microbial metabolites with CVD incidence. This study is a systematic review of twenty-one studies of which 19 were prospective cohort studies, one study included one nested case-control study and one study included two nested case–control studies. Results show that: - associations of trimethylamine N-oxide (TMAO) [molecular metabolite derived from the gut flora] and subsequent risk of CV outcomes were supported by some but not all prospective studies. - inconsistent results were also obtained for secondary bile acids in relation to CVD and related outcomes, and CVD/all-cause mortality. - with regards to branched-chain amino acids (BCAAs), their associations with CV outcomes were robust amongst most of the studies. Authors conclude that their findings show inconsistent results for TMAO and bile acids but robust ones for the relationships between BCAAs and CVD. Thus, further studies are needed to investigate whether circulating microbial metabolites could be an intervention target for CVD.
Abstract
Gut microbiota-derived metabolites have recently attracted considerable attention due to their role in host-microbial crosstalk and their link with cardiovascular health. The MEDLINE-PubMed and Elsevier's Scopus databases were searched up to June 2022 for studies evaluating the association of baseline circulating levels of trimethylamine N-oxide (TMAO), secondary bile acids, short-chain fatty acids (SCFAs), branched-chain amino acids (BCAAs), tryptophan and indole derivatives, with risk of cardiovascular disease (CVD). A total of twenty-one studies were included in the systematic review after evaluating 1210 non-duplicate records. There were nineteen of the twenty-one studies that were cohort studies and two studies had a nested case-control design. All of the included studies were of high quality according to the "Newcastle-Ottawa Scale". TMAO was positively associated with adverse cardiovascular events and CVD/all-cause mortality in some, but not all of the included studies. Bile acids were associated with atrial fibrillation and CVD/all-cause mortality, but not with CVD. Positive associations were found between BCAAs and CVD, and between indole derivatives and major adverse cardiovascular events, while a negative association was reported between tryptophan and all-cause mortality. No studies examining the relationship between SCFAs and CVD risk were identified. Evidence from prospective studies included in the systematic review supports a role of microbial metabolites in CVD.
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Dietary macronutrients and the gut microbiome: a precision nutrition approach to improve cardiometabolic health.
Jardon, KM, Canfora, EE, Goossens, GH, Blaak, EE
Gut. 2022;71(6):1214-1226
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The global rise in the prevalence of obesity is strongly associated with an increase in the incidence and prevalence of cardiometabolic diseases, including insulin resistance (IR) and type 2 diabetes mellitus. In recent years, advancements have been made in understanding the involvement of the gut microbiome in obesity and related cardiometabolic complications as regulator of host energy and substrate metabolism. This study is a review that discusses the latest research describing interactions between dietary composition, the gut microbiome and host metabolism. Results show that current evidence for developing optimal dietary interventions targeting bodyweight control and IR via the gut microbiota is still in its infancy and does not capture the complexity of the integration of a whole-diet approach, the microbial and the host’s metabolic phenotype. Furthermore, implementation of targeted, precision nutrition intervention strategies or dietary guidelines for individuals or subgroups in public health requires further insight in the mechanisms involved in (non-)response to dietary intervention. Authors conclude that future studies are needed and these should focus on assessing detailed individual phenotyping and gaining insight into the balance between carbohydrate and protein fermentation by the gut microbiota as well as the site of fermentation in the colon.
Abstract
Accumulating evidence indicates that the gut microbiome is an important regulator of body weight, glucose and lipid metabolism, and inflammatory processes, and may thereby play a key role in the aetiology of obesity, insulin resistance and type 2 diabetes. Interindividual responsiveness to specific dietary interventions may be partially determined by differences in baseline gut microbiota composition and functionality between individuals with distinct metabolic phenotypes. However, the relationship between an individual's diet, gut microbiome and host metabolic phenotype is multidirectional and complex, yielding a challenge for practical implementation of targeted dietary guidelines. In this review, we discuss the latest research describing interactions between dietary composition, the gut microbiome and host metabolism. Furthermore, we describe how this knowledge can be integrated to develop precision-based nutritional strategies to improve bodyweight control and metabolic health in humans. Specifically, we will address that (1) insight in the role of the baseline gut microbial and metabolic phenotype in dietary intervention response may provide leads for precision-based nutritional strategies; that (2) the balance between carbohydrate and protein fermentation by the gut microbiota, as well as the site of fermentation in the colon, seems important determinants of host metabolism; and that (3) 'big data', including multiple omics and advanced modelling, are of undeniable importance in predicting (non-)response to dietary interventions. Clearly, detailed metabolic and microbial phenotyping in humans is necessary to better understand the link between diet, the gut microbiome and host metabolism, which is required to develop targeted dietary strategies and guidelines for different subgroups of the population.
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Effects of early-life antibiotics on the developing infant gut microbiome and resistome: a randomized trial.
Reyman, M, van Houten, MA, Watson, RL, Chu, MLJN, Arp, K, de Waal, WJ, Schiering, I, Plötz, FB, Willems, RJL, van Schaik, W, et al
Nature communications. 2022;13(1):893
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Disturbances of the gut microbial community composition after birth are associated with a broad spectrum of health problems in early infancy and later in life. The ecological side effects of antibiotics may be even more pronounced and persistent when administered in the early assembly phase of the neonatal gut microbiome in the first weeks of life. The aim of this study was to identify the antibiotic regimen with the least ecological and antimicrobial resistance (AMR) gene selection effects. This study was a randomised controlled study in 147 infants who required broad-spectrum antibiotics for treatment of (suspected) early-onset neonatal sepsis (sEONS) in their first week of life. Infants were randomly allocated 1:1:1 to three most commonly prescribed intravenous antibiotic combinations. Results showed that antibiotic-treated infants show temporarily reduced gut microbial diversity, and major and prolonged ecological perturbations, compared with healthy term-born controls. Furthermore, there was also a shift in AMR gene profile. Authors conclude that there are significant long-term effects of broad-spectrum antibiotic treatment. In fact, their findings suggest that more emphasis should be put on reducing the number of neonates that receive broad-spectrum antibiotics for sEONS.
Abstract
Broad-spectrum antibiotics for suspected early-onset neonatal sepsis (sEONS) may have pronounced effects on gut microbiome development and selection of antimicrobial resistance when administered in the first week of life, during the assembly phase of the neonatal microbiome. Here, 147 infants born at ≥36 weeks of gestational age, requiring broad-spectrum antibiotics for treatment of sEONS in their first week of life were randomized 1:1:1 to receive three commonly prescribed intravenous antibiotic combinations, namely penicillin + gentamicin, co-amoxiclav + gentamicin or amoxicillin + cefotaxime (ZEBRA study, Trial Register NL4882). Average antibiotic treatment duration was 48 hours. A subset of 80 non-antibiotic treated infants from a healthy birth cohort served as controls (MUIS study, Trial Register NL3821). Rectal swabs and/or faeces were collected before and immediately after treatment, and at 1, 4 and 12 months of life. Microbiota were characterized by 16S rRNA-based sequencing and a panel of 31 antimicrobial resistance genes was tested using targeted qPCR. Confirmatory shotgun metagenomic sequencing was executed on a subset of samples. The overall gut microbial community composition and antimicrobial resistance gene profile majorly shift directly following treatment (R2 = 9.5%, adjusted p-value = 0.001 and R2 = 7.5%, adjusted p-value = 0.001, respectively) and normalize over 12 months (R2 = 1.1%, adjusted p-value = 0.03 and R2 = 0.6%, adjusted p-value = 0.23, respectively). We find a decreased abundance of Bifidobacterium spp. and increased abundance of Klebsiella and Enterococcus spp. in the antibiotic treated infants compared to controls. Amoxicillin + cefotaxime shows the largest effects on both microbial community composition and antimicrobial resistance gene profile, whereas penicillin + gentamicin exhibits the least effects. These data suggest that the choice of empirical antibiotics is relevant for adverse ecological side-effects.
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Dynamics of gut microbiota during pregnancy in women with TPOAb-positive subclinical hypothyroidism: a prospective cohort study.
Wu, M, Chi, C, Yang, Y, Guo, S, Li, T, Gu, M, Zhang, T, Gao, H, Liu, R, Yin, C
BMC pregnancy and childbirth. 2022;22(1):592
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Subclinical hypothyroidism (SCH) in pregnancy refers to the elevation of thyroid stimulating hormone level with normal free T4 level. One third of women with SCH have been reported to test positive for anti-thyroid peroxidase antibody (TPOAb+). The aim of this study was to evaluate whether gut microbiota can be potential therapeutic targets for managing TPOAb+ SCH. This study was a nested, prospective observational cohort study. A total of 64 and 68 pregnant women with TPOAb+ and TPOAb negative SCH, respectively, were included in this study. Results showed that women who were diagnosed with TPOAb+ SCH in trimester (T)1 show distinct dynamics of gut microbiota from T2 to T3. Furthermore, changes in the abundances of three types of bacterial species were abnormal in the presence of levothyroxine treatment. Authors conclude that gut microbiota can serve as potential therapeutic targets for TPOAb+ SCH during pregnancy.
Abstract
BACKGROUND Anti-thyroid peroxidase antibody (TPOAb) positivity can contribute to inhibit thyroxine synthesis. Gut microbiota can interact with metabolic or immune diseases. However, dynamics of gut microbiota from the second (T2) to the third trimester (T3) in women with TPOAb-positive/negative subclinical hypothyroidism (TPOAb+/TPOAb- SCH) have not been reported. Therefore, we aimed to evaluate whether gut microbiota can be potential therapeutic targets for managing TPOAb+ SCH. METHODS In this single-center prospective cohort study, we observed gut microbiota dynamics by sequencing 16S rRNA from fecal samples collected in T2 (20-23+ 6 weeks) and T3 (28-33+ 6 weeks). TPOAb+/TPOAb- SCH were stratified depending on whether or not they used levothyroxine (LT4) during the pregnancy (LT4+/LT4-). Microbiome bioinformatics analyses were performed using QIIME2. The linear discriminant analysis effect size (LEfSe) was used for the quantitative analysis of biomarkers. Functional profiling was performed with PICRUSt2. RESULTS Distinct gut microbiota dynamics from T2 to T3 were noted in the TPOAb- (n = 68) and TPOAb+ (n = 64) SCH groups. The TPOAb+ LT4- group was characterized by enriched bacterial amplicon sequence variants (ASVs) of Prevotella in T2 and Bacteria, Lachnospirales, Lachnospiraceae, Blautia, and Agathobacter in T3 and by depleted ASVs of Gammaproteobacteria, Enterobacterales, and Enterobacteriaceae in T2 and Actinobacteriota, Coriobacteriia, Actinobacteria, Coriobacteriales, Bifidobacteriales, Bifidobacteriaceae, Bifidobacterium, Dorea formicigenerans, and Bifidobacterium longum in T3. The TPOAb+ LT4+ group was characterized by enriched bacterial ASVs of Blautia, Streptococcus salivarius, and Bifidobacterium longum in T3 and by depleted ASVs of Bacteroidota, Bacteroidia, Bacteroidales, and Prevotella in T2 and Agathobacter in T3. Moreover, we identified 53 kinds of metabolic functions that were mainly involved in sugar, lipid, and amino acid metabolism. CONCLUSIONS Our results indicated that low dynamics of gut microbiota composition and high dynamics of its metabolic function from T2 to T3 were associated with TPOAb+ SCH. We concluded that gut microbiota could be new targets for treatment of TPOAb+ SCH during pregnancy. TRIAL REGISTRATION This study was retrospectively registered at the Chinese Clinical Trial Registry (registration number ChiCTR2100047175 ) on June 10, 2021.
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Intestinal Microbial Composition of Children in a Randomized Controlled Trial of Probiotics to Treat Acute Gastroenteritis.
Horne, RG, Freedman, SB, Johnson-Henry, KC, Pang, XL, Lee, BE, Farion, KJ, Gouin, S, Schuh, S, Poonai, N, Hurley, KF, et al
Frontiers in cellular and infection microbiology. 2022;12:883163
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During the first few years of life the diversity of the gut microbiome increases with increasing age. Many factors influence the colonisation after birth and during infancy. There are some studies that have looked at the use of probiotics as a treatment for gastrointestinal distresses in children with some success. These studies however focus on the outcome. They do not consider the differences in gut microbiota in children and do not look at individual responses to probiotics. The purpose of this randomized, double-blinded, placebo-controlled trial was to understand the effect of a probiotic treatment on children under 4 years old admitted to the emergency department of hospital with acute diarrhea. 70 children were included (30 in the probiotic group, 32 placebo). Stool analyses were done on admission (day 0), then 5 days after administration of a probiotic or placebo and then again at day 28. The results showed that participants younger than 1 year had lower bacterial diversity than older children. The age of the child is a dominant factor in determining the overall diversity of the gut microbiome. Probiotic treatment for 5 days did not alter the composition of the gut microbiota. However, there was lower diversity in the presence of enteric bacterial pathogens; in particular, with C. difficile in stool samples. This study highlights that base line measurements should be included and that age is a key factor when designing future studies of this kind.
Abstract
UNLABELLED Compositional analysis of the intestinal microbiome in pre-schoolers is understudied. Effects of probiotics on the gut microbiota were evaluated in children under 4-years-old presenting to an emergency department with acute gastroenteritis. Included were 70 study participants (n=32 placebo, n=38 probiotics) with stool specimens at baseline (day 0), day 5, and after a washout period (day 28). Microbiota composition and deduced functions were profiled using 16S ribosomal RNA sequencing and predictive metagenomics, respectively. Probiotics were detected at day 5 of administration but otherwise had no discernable effects, whereas detection of bacterial infection (P<0.001) and participant age (P<0.001) had the largest effects on microbiota composition, microbial diversity, and deduced bacterial functions. Participants under 1 year had lower bacterial diversity than older aged pre-schoolers; compositional changes of individual bacterial taxa were associated with maturation of the gut microbiota. Advances in age were associated with differences in gut microbiota composition and deduced microbial functions, which have the potential to impact health later in life. CLINICAL TRIAL REGISTRATION www.ClinicalTrials.gov, identifier: NCT01853124.