Introduction

Antibiotic-associated diarrhea frequently arises due to disruptions in the intestinal microbiome, often becoming severe in elderly individuals. Such instances of diarrhea are also notably prevalent during Helicobacter pylori eradication, affecting approximately 26.6% of patients [1]. The composition and diversity of gut microbiota vary with age, suggesting that the frequency of diarrhea associated with antibiotic disruption of the gut flora, as well as sensitivity to probiotics, may differ across age groups.

Aims & Methods

Aims: This study aims to examine the differences in the frequency of diarrhea and disruption of the microbiome during Helicobacter pylori eradication between elderly and younger Japanese adults, and to evaluate the effectiveness of the antibiotic-resistant probiotic Enterococcus faecium 129 BIO 3B-R in mitigating these effects.
Methods: Seventy-six Japanese adults undergoing Helicobacter pylori eradication treatment were enrolled in the study and categorized into two groups: those aged 70 and above (elderly) and those under 70 (younger adults). The diversity of the gut microbiota prior to treatment initiation was assessed using meta 16S sequencing to evaluate differences between the two age groups. Participants were randomly assigned to receive either a resistant lactic acid bacteria preparation (Enterococcus faecium 129 BIO 3B-R) or a placebo in a blind manner, and the incidence of diarrhea and changes in microbiota composition were analyzed.

Results

Results: Meta 16S rDNA sequencing analysis revealed distinct microbiota compositions between younger and elderly adults, with significantly higher alpha diversity observed in the elderly. LEfSe analysis showed a higher abundance of the Lactobacillus and Blautia genera and a lower presence of Bammaproteobacteria class in the elderly group. The frequency of antibiotic-induced dysbiosis-related diarrhea was compared between younger and elderly adults, showing a higher tendency in the elderly, although there was no significant difference in the extent of diversity reduction between the age groups. Administration of the resistant lactic acid bacteria preparation, Enterococcus faecium 129 BIO 3B-R, resulted in a lower frequency of diarrhea and a tendency to preserve alpha diversity in the microbiota of the elderly compared to the placebo group.

Conclusion

Elderly individuals, with their distinct gut microbiota composition and diversity compared to younger adults, may have different susceptibilities to antibiotic-induced diarrhea. Furthermore, incorporating resistant lactic acid bacteria as a supplementary treatment could be advantageous for managing diarrhea and stabilizing the gut flora in the elderly.

References

[1] Armuzzi A, Cremonini F, Bartolozzi F, et al. The effect of oral administration of Lactobacillus GG on antibiotic-associated gastrointestinal side-effects during Helicobacter pylori eradication therapy. Aliment Pharmacol Ther. 2001;15:163–169.

Disclosure

This work was supported by a research grant from Biofermin Pharmaceutical Co. Ltd.

Introduction

H. pylori eradication therapy induces significant alterations in the gut microbiome. While probiotics have been extensively studied as a potential strategy to mitigate microbiota-related consequences of antibiotics, their efficacy remains a subject of debate.

Aims & Methods

The aim of our study was to evaluate the influence of butyric acid+inulin supplements on gut microbiota changes (including gut microbiota taxonomic composition, functional potential, and gut resistome) induced by H.pylori eradication therapy. A total of 22 H. pylori-positive patients aged 19 to 64 years were enrolled in the study. Patients were randomized into two H. pylori eradication regimens: 1) ECAB-14: esomeprazole 20 mg, clarithromycin 500 mg, amoxicillin 1000 mg, and bismuthate tripotassium dicitrate 240 mg, twice daily, orally, for 14 days. 2) ECAB-Z-14: esomeprazole 20 mg, clarithromycin 500 mg, amoxicillin 1000 mg, and bismuthate tripotassium dicitrate 240 mg, twice daily, along with butyric acid+inulin (Zacofalk) supplementation (two tablets daily, each containing 250 mg of butyric acid and 250 mg of inulin), orally, for 14 days. Stool samples were collected from each subject at three time points: prior to eradication therapy (I), after therapy completion (II), and one month post-therapy (III). Total DNA from fecal samples was isolated for whole genome sequencing using the Illumina NextSeq 500 platform.

Results

Gut Microbiota Alpha Diversity (Shannon Index): Immediately after eradication therapy, both the ECAB-14 and ECAB-Z-14 groups experienced a significant decrease in gut microbiota alpha diversity compared to the initial level: (2.46 ± 1.06) vs. (3.75 ± 0.342), p = 0.0029, and (3.22 ± 0.73) vs. (3.82 ± 0.30), p = 0.037, respectively. After one month, the Shannon index was restored to the baseline level in the ECAB-Z-14 treatment group: no statistically significant differences were identified between time points III and I [(3.71 ± 0.33) vs. (3.82 ± 0.30), p = 0.206]. However, even a month after therapy, the ECAB-14 treatment group still exhibited a lower Shannon index than the baseline level [(3.27 ± 0.39) vs. (3.75 ± 0.342), p = 0.019].
Functional Potential Alterations: In the ECAB-Z-14 treatment group, less pronounced alterations in gut microbiota functional potential were observed. Specifically, 72 metabolic pathways changed immediately after eradication therapy. In contrast, the ECAB-14 group showed impact on 112 signaling pathways.
Butyrate Production Genes: The abundance of genes associated with butyrate production decreased only in the ECAB-14 treatment group. However, in the ECAB-Z-14 treatment group, the abundance of genes responsible for butyrate production remained stable.
Antibiotic Resistance Genes: The prevalence of gut microbiota antibiotic resistance genes increased significantly in both treatment groups immediately after eradication. Notably, more severe alterations were observed in the ECAB-14 treatment group, where the abundance of 73 antibiotic resistance genes significantly increased. Meanwhile, the ECAB-Z-14 group showed an increase in only 50 antibiotic resistance genes immediately after eradication therapy.

Conclusion

H. pylori eradication therapy significantly affects gut microbiota composition, functional potential, and increases the abundance of antibiotic resistance genes. However, the addition of butyric acid+inulin supplements to the H. pylori eradication regime may mitigate these effects.

Introduction

Gut micorbiota in patients with cystic fibrosis (pwCF) is severely disrupted and a potential source of further complications. We aim to provide quantitative evidence of the differences in gut microbiota between pwCF and non-CF controls to understand CF gut flora composition and identify potential sites for microbiota modulation with special focus on time-dependent changes.

Aims & Methods

We conducted a systematic review and meta-analysis of PubMed, EMBASE, CENTRAL, Web of Science, and Scopus up to November 13, 2023 (CRD42023482792). Included were case-control studies assessing gut microbial alpha diversity or relative abundance in pwCF and controls without gut-affecting conditions or drugs. Standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated using a random-effects model for both outcomes. We performed subgroup analysis for alpha diversity for infants, children, and adults. We used the Joanna Briggs Institute risk of bias tool.

Results

Among 2550 studies, 11 met inclusion criteria (enrolling 1174 subjects). Alpha diversity analysis showed age-specific changes. Observed OTUs were non-significantly decreased in adult pwCF compared to controls (SMD=-1.57; 95%CI -4.21 to 1.08, across 3 studies, 80 pwCF and 100 controls). Children with CF displayed a significantly reduced Shannon index (SMD=-1.43; 95%CI -2.06 to -0.79, across 3 studies, 77 pwCF and 78 controls). However, in infants, no difference was detected in Shannon index between CF patients and controls (SMD=0.05; 95%CI -0.74 to 0.84, across 4 studies, 288 pwCF, 519 controls). Analysis of follow-up data in infants revealed a decreasing tendency of Shannon index in pwCF compared to controls during the first year of life (SMD=0.67; 95%CI -1.20 to 2.54 at 4 months vs. SMD=0.45; 95%CI -1.81 to 2.71 at 6 months vs. SMD=-0.61; 95%CI -1.98 to 0.75 at 12 months). A significant increase in the relative abundance of Veillonella and E.coli marked the CF group with a noticeable increase of Enterobacter and decrease of Bacteroides and Faecalibacterium compared to controls (see Table).

Taxon name	No of studies	No of pwCF and controls	Level of taxonomic order	Standardised mean difference	Confidence interval (95%)	Heterogeneity
Actinobacteria	4	219/93	Phylum	-0.12	-1.04 – 0.80	69%
Bacteroides	4	96/512	Genus	-0.53	-2.04 – 0.98	93%
Blautia	4	96/512	Genus	-0.14	-0.51 – 0.24	0%
Enterobacter	3	255/461	Genus	0.32	-0.11 – 0.76	0%
Enterococcus	4	96/512	Genus	0.07	-0.70 – 0.83	70%
Faecalibacterium	3	75/103	Genus	-0.32	-2.01 – 1.37	83%
Streptococcus	4	96/512	Genus	0.16	-0.79 – 1.11	79%
Veillonella	4	96/512	Genus	0.97	0.04 – 1.90	78%
E.coli	4	213/107	Species	0.65	0.10 – 1.20	33%

Conclusion

Gut microbial alpha diversity is reduced in adults and children with CF compared to controls, while infants with CF exhibit similar diversity, which continuously decreases during the first year of life. Perturbations in the intestinal microbial ecosystem are defined by a significant increase in E.coli and Veillonella abundances within individuals with CF compared to controls enabling specifically targeted microbiota modulation.

Introduction

Recent years have seen a significant increase in randomized controlled trials (RCT) published on the efficacy of probiotics on irritable bowel syndrome (IBS), which several reviews have tried to comprehensively review. Two recent trials, Yang et al. 2024¹ and Chen et al. 2023² report the safety and efficacy of probiotics for IBS, which seems to reflect prevailing favorable view of this therapeutic option by most reviews conducted. Yet, despite efforts in this field, major organizations have not changed their stance in this and make no assertive recommendation for probiotics in afflicted patients^3,4. While further investigations are required, two challenges are faced: (1) repeated reviews have been undertaken in this field, resulting in a "multiplicity problem", (2) traditional meta-analytic techniques may also fail to provide a conclusive answer on the sufficiency of evidence, particularly when the data are sparse, and the risk of type I and type II errors is significant. This indicates a need for.

Aims & Methods

This study aims to evaluate the efficacy of probiotics in alleviating symptoms of IBS and improve quality of life through a timely implemented trial sequential analysis (TSA) and rigorously evaluate the evidence for recommendations on future studies. Medline, Embase, Web of Science, and Cochrane were screened for randomized controlled trials (RCTs) comparing probiotics to placebo in adult patients with IBS. Primary outcomes included IBS Symptom Severity Score (IBS-SSS) and IBS Quality of Life (IBS-QOL) scores comparing probiotics and placebo groups. Traditional pairwise meta-analysis conducted in restricted maximum likelihood was conducted, with subsequent TSA . Study quality was graded according to risk-of-bias 2 (ROB-2) and certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

Results

42 studies were included. Overall, probiotics demonstrated non-significant improvements in IBS-SSS (MD: -27.64; 95% CI: -56.90 to 1.63; p=0.06) and IBS-QOL (MD: 1.33; 95% CI: -3.65 to 6.30; p=0.59). TSA was conducted on IBS-SSS demonstrated current evidence has not reached the required information size. The representative cumulative Z-curve demonstrated neither futility, benefit nor detrimental effect, indicating the need for further trials. Assessment with ROB-2 indicates high quality amongst most trials included in this study. GRADE evaluation of the evidence demonstrated low certainty of existing evidence.

Table 1: GRADE Evaluation

No. of studies	Study design	Risk of bias	Inconsistency	Indirectness	Imprecision	Other considerations	Probiotics	Placebo	Relative (95% CI)	Absolute (95% CI)	Certainty
Probiotics effectively reduces a patient's IBS-SSS score
24	randomised trials	not seriousa	very seriousb	not serious	very seriousc	publication bias strongly suspectedd	2237	1599	-	MD 27.64 lower (56.9 lower to 1.63 higher)	⨁◯◯◯ Very lowa,b,c,d
Probiotics effectively reduces a patient's IBS-QOL score
24	randomised trials	not seriousa	very seriousb	not serious	not seriouse	publication bias strongly suspectedd	2292	1712	-	MD 1.33 higher (3.65 lower to 6.3 higher)	⨁◯◯◯ Very lowa,b,d,e

CI: confidence interval; MD: mean difference

Two contributing factors to the low certainty of current evidence include: (1) Inconsistency of existing trials – there exists high level of heterogeneity as detected by statistical analysis through I² and Cochran Q amongst studies; (2) Suspected publication bias through inspection of a funnel plot, though Egger’s regression did not demonstrate statistical significance.

Conclusion

Existing evidence is insufficient to make conclusive recommendations regarding the role probiotics should play in the management of IBS in symptoms and QOL. Given the persistent heterogeneity and potential publication bias, future research should focus on standardizing probiotic interventions and clarifying their clinical utility to truly advance the field.

References

1. Yang R, Jiang J, Ouyang J, Zhao Y, Xi B. Efficacy and safety of probiotics in irritable bowel syndrome: a systematic review and meta-analysis. Clinical Nutrition ESPEN. 2024;
2. Chen M, Yuan L, Xie C-R, et al. Probiotics for the management of irritable bowel syndrome: a systematic review and three-level meta-analysis. International Journal of Surgery. 2023;109(11):3631-3647.
3. Su GL, Ko CW, Bercik P, et al. AGA Clinical Practice Guidelines on the Role of Probiotics in the Management of Gastrointestinal Disorders. Gastroenterology. 2020;159(2):697-705. doi:10.1053/j.gastro.2020.05.059
4. McKenzie Y, Thompson J, Gulia P, Lomer M. British Dietetic Association systematic review of systematic reviews and evidence‐based practice guidelines for the use of probiotics in the management of irritable bowel syndrome in adults (2016 update). Journal of Human Nutrition and Dietetics. 2016;29(5):576-592.
5. Lacy BE, Pimentel M, Brenner DM, et al. ACG clinical guideline: management of irritable bowel syndrome. Official journal of the American College of Gastroenterology| ACG. 2021;116(1):17-44.

Disclosure

All authors of the manuscript do not have a conflict of interest to declare.

Introduction

Understanding the intra- and inter-individual variability of gut microbiota is crucial for advancing microbiota research and its clinical applications. Gut microbial markers play essential roles in maintaining intestinal health, with functional groups including opportunistic, proteolytic, equilibrium, immunoprotective, mucosal homeostasis, proinflammatory, and methanogenic microbes.

Aims & Methods

This study aimed to evaluate the temporal stability of 15 microbial markers and identify potential transient disruptions associated with lifestyle and dietary factors.
A longitudinal observational study was conducted with 6 participants, including 4 healthy individuals and 2 with mild IBS, each providing 7 fecal samples (42 samples total) over a one-month period on randomly selected days. Microbial DNA was extracted from fecal samples and analyzed using a qPCR kit of a specific microbiota test, which includes a panel of 15 microbial markers. Participants completed questionnaires on each sampling day, documenting dietary habits, lifestyle factors, and digestive health. To assess the stability of the microbial markers in relation to differences among individuals, the Intraclass Correlation Coefficient (ICC) was calculated after adjusting a mixed effects model for each marker. These metrics provide numerical insights into the consistency and variability of the microbial populations over time. However, it is essential to contrast these numbers with the nature or behaviour of each marker, allowing for a more accurate and contextualized interpretation of the results, as the observed variability and stability may be influenced by intrinsic factors to each type of microbial marker.

Results

Distinct individual-specific microbiota patterns were observed, with clear inter-individual variability in baseline distributions. Transient alterations were observed in some cases, with many of them associated with dietary factors, such as specific food types or eating habits reported prior to sample collection. Notably, indicative markers of intestinal health, such as Faecalibacterium prausnitzii, Roseburia, and Ruminococcus, remained stable. In contrast, modifications in Akkermansia muciniphila and Methanobrevibacter smithii levels were observed coincident with variations in dietary intake suggesting that these could be an influent factor. Particularly, these disruptions were generally short-lived, with markers returning to baseline levels within a few days. The ICC has demonstrated its effectiveness in refining results and quantifying the relationship among intra- and inter-personal variability of markers. For example, Faecalibacterium prausnitzii exhibited a low ICC (0.112), indicating minimal differences among participants, whereas Methanobrevibacter smithii had a high ICC (0.921), reflecting significant variability among participants.

Conclusion

This study provides preliminary insights into the stability and individual variability of gut microbiota markers analyzed using the qPCR kit of this microbiota test. These findings highlight the importance of establishing personal baselines for accurate diagnostic interpretation and underscore the resilience of the gut microbiota in response to daily lifestyle fluctuations Moreover, the stability of intestinal health indicators markers supports their potential as reliable indicators of gut health. These results provide valuable data for a deeper understanding of gut health dynamics and underscore the importance of personalized approaches in microbiota diagnostics and management.

Disclosure

This work has been previously presented at an international meeting.
Authors: Lia Oliver, Marta Malagón, Mariona Serra-Pagès, and Daniel Rius are employees of GoodGut SLU. Xavier Aldeguer has also collaborated with GoodGut as a medical advisor.
Funding: This project has been partially funded by the AGAUR grant for Industrial Doctorates.