Relationship between Nutrient Intake and Human Gut Microbiota in Monozygotic Twins

Study of gut microbiome alterations in plaque psoriasis patients compared to healthy individuals

Introduction

Many studies have shown significant alterations in the gut microbiome of patients with psoriasis compared to healthy controls.

Aim

The primary objective of the current research was to explore the impact of gut microbiome composition on the progression and severity of plaque psoriasis.

Material and methods

A total of 20 patients with moderate-to-severe psoriasis and 20 healthy individuals were recruited and provided a stool sample to assess the gut microbiome. After the samples were prepared according to the NGS library preparation workflow, they were sequenced using the Illumina platform and the report was generated that underwent statistical analysis.

Results

The microbiome profiles of psoriasis patients exhibited significant differences compared to healthy controls as evidenced by the statistical analysis of various bacterial genera, with the median abundance significantly lower in psoriasis patients compared to healthy controls (p = 0.033). The analysis of the Firmicutes-to-Bacteroidetes ratio, a commonly evaluated marker of dysbiosis, did not reach statistical significance (p = 0.239). However, there was a noticeable trend towards a higher median ratio in psoriasis patients compared to healthy controls. The ratio did not show significant associations with PASI or BSA but trends towards significance with DLQI (B = -12.11, p = 0.095).

Conclusions

Overall, the above findings underscore the importance of the gut microbiome in psoriasis and suggest that modulation of specific bacterial genera, especially that with significant differences, could be a potential strategy for therapeutic intervention. Targeting these depleted genera through microbiome-based interventions, such as probiotic supplementation or faecal microbiota transplantation, could potentially help to restore gut homeostasis and alleviate the inflammatory burden in psoriasis.

Impact of the gut microbiome on immunological responses to COVID-19 vaccination in healthy controls and people living with HIV

Although mRNA SARS-CoV-2 vaccines are generally safe and effective, in certain immunocompromised individuals they can elicit poor immunogenic responses. Among these individuals, people living with HIV (PLWH) have poor immunogenicity to several oral and parenteral vaccines. As the gut microbiome is known to affect vaccine immunogenicity, we investigated whether baseline gut microbiota predicts immune responses to the BNT162b2 mRNA SARS-CoV-2 vaccine in healthy controls and PLWH after two doses of BNT162b2. Individuals with high spike IgG titers and high spike-specific CD4+ T-cell responses against SARS-CoV-2 showed low α-diversity in the gut. Here, we investigated and presented initial evidence that the gut microbial composition influences the response to BNT162b2 in PLWH. From our predictive models, Bifidobacterium and Faecalibacterium appeared to be microbial markers of individuals with higher spike IgG titers, while Cloacibacillus was associated with low spike IgG titers. We therefore propose that microbiome modulation could optimize immunogenicity of SARS-CoV-2 mRNA vaccines.

Gut Microbiota in Patients with Postoperative Atrial Fibrillation Undergoing Off-Pump Coronary Bypass Graft Surgery

BACKGROUND

Post-operative atrial fibrillation (POAF) is one of the most common complications of cardiac surgery. However, the underlying mechanism is not well understood. Alterations in the gut microbiota are associated with the development of atrial fibrillation (AF). The aim of this study was to explore the relationship between gut microbiota and POAF.

METHODS

Fecal samples were collected before surgery from 45 patients who underwent coronary artery bypass grafting with POAF and 90 matched patients without POAF (1:2). 16S rRNA sequencing was used to detect the microbiome profiles of 45 POAF patients and 89 matched patients (one sample in the no-POAF group was deleted owing to low quality after sequencing). Plasma 25-hydroxy vitamin D level was measured by ELISA.

RESULTS

Compared to the patients without POAF, gut microbiota composition was remarkably changed in the patients with POAF, with an increase in Lachnospira, Acinetobacter, Veillonella and Aeromonas, and a decrease in Escherichia-Shigella, Klebsiella, Streptococcus, Brevundimonas and Citrobacter. Furthermore, plasma 25-hydroxy vitamin D levels were decreased in POAF patients and negatively correlated with an abundance of Lachnospira.

CONCLUSIONS

The gut microbiota composition between patients with and without POAF is significantly different, implying that gut microbiota may play a role in the pathogenesis of POAF. Further studies are needed to fully clarify the role of gut microbiota in the initiation of AF.

Components of the Fiber Diet in the Prevention and Treatment of IBD-An Update

Inflammatory bowel disease (IBD) is a group of diseases with a chronic course, characterized by periods of exacerbation and remission. One of the elements that could potentially predispose to IBD is, among others, a low-fiber diet. Dietary fiber has many functions in the human body. One of the most important is its influence on the composition of the intestinal microflora. Intestinal dysbiosis, as well as chronic inflammation that occurs, are hallmarks of IBD. Individual components of dietary fiber, such as β-glucan, pectin, starch, inulin, fructooligosaccharides, or hemicellulose, can significantly affect preventive effects in IBD by modulating the composition of the intestinal microbiota or sealing the intestinal barrier, among other things. The main objective of the review is to provide information on the effects of individual fiber components of the diet on the risk of IBD, including, among other things, altering the composition of the intestinal microbiota.

Leishmania infantum infection does not affect the main composition of the intestinal microbiome of the Syrian hamster

BACKGROUND

Visceral leishmaniasis (VL) is the most severe form of all leishmanial infections and is caused by infection with protozoa of Leishmania donovani and Leishmania infantum. This parasitic disease occurs in over 80 countries and its geographic distribution is on the rise. Although the interaction between the intestinal microbiome and the immune response has been established in several pathologies, it has not been widely studied in leishmaniasis. The Syrian hamster is the most advanced laboratory model for developing vaccines and new drugs against VL. In the study reported here, we explored the relationship between the intestinal microbiome and infection with L. infantum in this surrogate host.

METHODS

Male Syrian hamsters (120-140 g) were inoculated with 108 promastigotes of a canine-derived L. infantum strain or left as uninfected control animals. Infection was maintained for 19 weeks (endpoint) and monitored by an immunoglobulin G (IgG) enyzme-linked immunosorbent assay throughout the experiment. Individual faecal samples, obtained at weeks 16, 18 and 19 post-inoculation, were analysed to determine the 16S metagenomic composition (the operational taxonomic units [OTUs] of the intestinal microbiome and the comparison between groups were FDR (false discovery rate)-adjusted).

RESULTS

Leishmania infantum infection elicited moderate clinical signs and lesions and a steady increase in specific anti-Leishmania serum IgG. The predominant phyla (Firmicutes + Bacteriodetes: > 90%), families (Muribaculaceae + Lachnospiraceae + Ruminococcaceae: 70-80%) and genera found in the uninfected hamsters showed no significant variations throughout the experiment. Leishmania infantum infection provoked a slightly higher-albeit non-significant-value for the Firmicutes/Bacteriodetes ratio but no notable differences were found in the relative abundance or diversity of phyla and families. The microbiome of the infected hamsters was enriched in CAG-352, whereas Lachnospiraceae UCG-004, the [Eubacterium] ventriosum group and Allobaculum were less abundant.

CONCLUSIONS

The lack of extensive significant differences between hamsters infected and uninfected with L. infantum in the higher taxa (phyla, families) and the scarce variation found, which was restricted to genera with a low relative abundance, suggest that there is no clear VL infection-intestinal microbiome axis in hamsters. Further studies are needed (chronic infections, co-abundance analyses, intestinal sampling, functional analysis) to confirm these findings and to determine more precisely the possible relationship between microbiome composition and VL infection.

Progress in application of probiotics, prebiotics, and synbiotics in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common functional bowel disorder characterized by recurrent abdominal pain accompanied by changes in defecation frequency and/or stool characteristics. The global incidence of IBS is increasing year by year. Intestinal symptoms caused by IBS (such as constipation, diarrhea, abdominal pain, and abdominal distension) and accompanying changes in general nervous system function can significantly reduce patients' quality of life and work efficiency, and lead to high medical costs. Therefore, finding safe, effective, and economical treatments has become a hot research topic in recent years. Studies have shown that the intestinal flora of patients with IBS is different from that of healthy subjects, and regulating the intestinal flora can treat IBS. The purpose of this review is to summarize the application and recent progress of probiotics, prebiotics, and synbiotics in the treatment of IBS by regulating the intestinal flora.

Microbiota's Role in Diet-Driven Alterations in Food Intake: Satiety, Energy Balance, and Reward

The gut microbiota plays a key role in modulating host physiology and behavior, particularly feeding behavior and energy homeostasis. There is accumulating evidence demonstrating a role for gut microbiota in the etiology of obesity. In human and rodent studies, obesity and high-energy feeding are most consistently found to be associated with decreased bacterial diversity, changes in main phyla relative abundances and increased presence of pro-inflammatory products. Diet-associated alterations in microbiome composition are linked with weight gain, adiposity, and changes in ingestive behavior. There are multiple pathways through which the microbiome influences food intake. This review discusses these pathways, including peripheral mechanisms such as the regulation of gut satiety peptide release and alterations in leptin and cholecystokinin signaling along the vagus nerve, as well as central mechanisms, such as the modulation of hypothalamic neuroinflammation and alterations in reward signaling. Most research currently focuses on determining the role of the microbiome in the development of obesity and using microbiome manipulation to prevent diet-induced increase in food intake. More studies are necessary to determine whether microbiome manipulation after prolonged energy-dense diet exposure and obesity can reduce intake and promote meaningful weight loss.

Probiotics, Prebiotics, and Synbiotics in the Irritable Bowel Syndrome Treatment: A Review

Irritable bowel syndrome is not a life-threatening disease, yet it significantly affects the quality of life and contributes to economic loss. It is estimated that even up to 45% of the world's population can suffer from the disease. The first attempts to diagnose irritable bowel syndrome were made at the end of the 19th century; however, establishing appropriate diagnostic criteria and treatment methods is still ongoing. To date, little is known about the etiology of irritable bowel syndrome; however, growing attention is drawn to the intestinal microbiota as a factor in the disease development. For this reason, researchers have conducted many studies on therapies that modulate the microbiota, among which probiotics, prebiotics, and synbiotics are widely studied. To date, most studies have examined probiotics; however, there are also several studies demonstrating the efficacy of prebiotics and synbiotics. The aim of this review was to summarize findings on the usefulness of probiotics, prebiotics, and synbiotics in the treatment of irritable bowel syndrome.