Host genetics and gut microbiota composition: Baseline gut microbiota composition as a possible prognostic factor for the severity of COVID-19 in patients with familial Mediterranean fever disease

Gut Akkermansia muciniphila, Prevotellaceae, and Enterobacteriaceae spp. as Possible Markers in Women-Related Nutritional and Clinical Trials: Familial Mediterranean Fever Disease

Background

Studies have shown that the gut microbiota of healthy men and men with familial Mediterranean fever (FMF) disease respond differently to placebo. Given the fact that the composition of the gut microbiota is different in men and women, this study aimed to describe in detail the placebo response of the gut microbiota in healthy and FMF women.

Materials and Methods

The bacterial response to placebo was fully evaluated on a previous PhyloChip™ DNA microarray-based assay (GEO Series; accession number GSE111835).

Results

The change in the total number of operational taxonomic units in healthy women exposed to placebo is more than that of healthy men, in contrast to FMF people (704 vs. 140 and 409 vs. 7560, respectively [p < 0.05]). Gut Firmicutes diversities are more sensitive to placebo, whereas Akkermansia muciniphila remained unchanged after the placebo administration for both healthy and FMF people. Gut Prevotellaceae and Enterobacteriaceae diversities of healthy subjects and FMF women are also almost unchanged from placebo. Meanwhile, only 56.35% of gut Enterobacteriaceae diversities in FMF men were placebo resistant.

Conclusion

The response to a placebo varies depending on a person's gender and health status. Healthy and FMF women's placebo study groups could be avoided by excluding placebo-sensitive 704 of 18,725 and 409 of 18,725 bacterial diversities, respectively. Because the placebo causes changes in all gut bacterial phyla in healthy and FMF women, and only the representatives of Enterobacteriaceae and Prevotellaceae families and A. muciniphila spp. are not affected by placebo, these bacteria can be considered as possible markers in women-related nutritional/clinical trials. Data on the response of the gut microbiota in healthy women to placebo might be used in studies of diseases other than FMF. The response of gut bacteria from different taxonomic affiliations to placebo may provide a basis for uncovering the role of these bacteria in the gut-brain axis.

Challenges for heat stress: Intestinal culturable bacteria of Lohmann Brown chickens

This study aimed to assess how heat stress, specifically within the range of 35-38 °C, affects the populations of culturable intestinal lactobacilli, enterococci, and Escherichia coli, as well as the expression of Heat Shock Proteins (HSP70), in Lohmann Brown chickens. It also explored the influence of the chickens' blood transferrin and ceruloplasmin genotypes on these responses. Thirty chickens underwent eight hours of heat stress, maintained at an average temperature of 37 °C and a relative humidity of 75-80%, with continuous access to food and water. Behavioral monitoring was conducted throughout to prevent excessive heat-related mortality. The Lohmann Brown chickens from the Yerevan "Arax" poultry farm were initially classified based on their blood transferrin and ceruloplasmin genotypes to investigate potential correlations between intestinal bacterial composition and variations in these polymorphisms. A significant correlation was found between heat stress and the abundance of culturable enterococci within the intestinal microbiota, regardless of chicken TfAB, TfBC, CpAB, CpCC and TfAB, TfBC, CpAB, CpCD genotypes. Heat stress led to nearly double the HSP70 levels in chicken blood, along with a reduction in the culturable enterococci population by at least 10,000-fold in the intestinal microbiota. These findings are significant for targeted management strategies to mitigate heat stress in chicken populations.

Placebo-resistant gut bacteria: Akkermansia muciniphila spp. and Familial Mediterranean fever disease

Introduction

Despite numerous investigations into the impact of drugs/probiotics on the gut microbiota composition in Familial Mediterranean Fever (FMF) patients, the question as to whether there exists a significant bacterial diversity(ies) independent of the placebo effect that can be reliably considered in clinical and nutritional trials remains unresolved.

Methods

This study represents the in augural analysis of the placebo's influence on the gut microbiota of both healthy individuals and FMF afflicted men, utilizing previously collected data from PhyloChip™ DNA microarray experiments. A total of 15 healthy and 15 FMF male volunteers, aged 18 to 50, participated in this partially randomized placebo trial, which is accessible through the GEO Series accession number GSE111835.

Results and Discussion

Key findings from current investigations include i. the anticipated divergence in gut bacteria resistance to placebo between healthy and FMF individuals, ii. the minor impact of placebo on gut bacterial diversities in healthy individuals, with Enterobacteriaceae diversities identified as placebo-resistant among "healthy" gut bacteria, and iii. the comprehensive influence of placebo on all bacterial phyla in the gut microbiome of FMF patients, extending to nearly all bacterial genera, except for the resilience of gut Akkermansia muciniphila spp. to placebo in FMF patients. This study underscores the susceptibility of Faecalibacterium, Blautia, and Clostridium genera to placebo. Consequently, this investigation holds significance for the proper design of placebo-controlled trials and establishes a foundation for further exploration of the gut-brain axis. Furthermore, it contributes valuable insights to discussions regarding proposals for probiotic therapies, particularly focusing on Faecalibacterium spp., Blautia spp., and Clostridium spp.