[The role of gut microbiota in the pathogenesis of obesity and diabetes]

The influence of nutritional habits, body mass index and intestinal microbiota in mastocytosis on clinical symptoms using conventional culture and next generation sequencing

BACKGROUND

Mastocytosis is a rare neoplastic disease of the bone marrow associated with the proliferation and accumulation of mast cells in various internal organs, including the gastrointestinal tract. There are few studies describing the gut microbiome of patients with mastocytosis using next generation sequencing supported using traditional culture methods. The aims of the study were, firstly, the determination of nutrition habits, composition of the intestinal microflora and BMI in mastocytosis, and secondly, analysis of mastocytosis severity and symptoms depending on the composition of the intestinal microflora.

METHODS

The study included 47 patients with indolent systemic mastocytosis and 18 healthy controls. All participants gave their informed consent to participate in the study. The study consisted of 3 parts: I-clinical assessment, II - examination of the intestinal microflora using the biochemical method, III - 16S rRNA sequencing.

RESULTS

The nutrition habits and BMI of mastocytosis patients were similar to controls; however, most patients with mastocytosis had a low dietary vitamin and mineral content. As many as 94.5% of patients had too little fiber intake and mineral content. The most common cause of the abnormal stool test result with traditional culture was a titer of E. coli <106 . The low richness of microbiota species indicated by the Simpson index was observed in mastocytosis, p = 0.04. There were no significant differences in the composition of the intestinal microflora depending on the type of mastocytosis; however, the tryptase level correlated with the amount of Suterella, Barnesiellaceae, Eubacterium, Odoribacter, and Anaerostipes.

CONCLUSIONS

The nutritional habits and BMI of mastocytosis patients are similar to the general population, except for too little fiber intake and mineral content. The gastrointestinal symptoms of mastocytosis patients may be related to the low richness of microbiota species and the amount of Suterella, Barnesiellaceae, Eubacterium, Odoribacter, Anaerostipes, which correlated with tryptase levels.

Shared and Distinct Gut Microbial Profiles in Saudi Women with Metabolically Healthy and Unhealthy Obesity

BACKGROUND

Mounting evidence suggests a pivotal role for the gut microbiome in energy disequilibrium characteristic of obesity. The clinical utility of microbial profiling for the distinction between metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO) remains ill-defined. We aim to probe microbial composition and diversity in young adult Saudi females with MHO and MUO. This observational study included anthropometric and biochemical measurements and shotgun sequencing of stool DNA for 92 subjects. α- and β-diversity metrics were calculated to determine the richness and variability in microbial communities, respectively. Results showed that Bacteroides and Bifidobacterium merycicum were less abundant in MUO compared to healthy and MHO groups. BMI was negatively correlated with B. adolescentis, B. longum, and Actinobacteria in MHO, while being positively correlated with Bacteroides thetaiotaomicron in both MHO and MUO. Positive correlations between waist circumference and B. merycicum and B. thetaiotaomicron were observed in MHO and MUO, respectively. Compared to MHO and MUO groups, higher α-diversity was detected in healthy individuals who also had higher β-diversity compared to those with MHO. We conclude that modulation of the gut microbiome cohorts through prebiotics, probiotics, and fecal microbiota transplantation may be a promising preventive and therapeutic approach to obesity-associated disease.

Assessing Effects of Diet Alteration on Carbohydrate-Lipid Metabolism of Antipsychotic-Treated Schizophrenia Patients in Interventional Study

This study aimed at finding whether healthy eating habits could be introduced to and maintained by chronically mentally ill permanent residents of a nursing home. Of interest was also if the effects of the dietary intervention would be observable as improved carbohydrate and lipid metabolism indicators were selected. Assays covered 30 antipsychotics-treated residents diagnosed with schizophrenia. The prospective method applied involved questionnaires, nutrition-related interviews, anthropometric measurements, and determination of selected biochemical parameters of the blood. The dietary intervention as well as the parallel health-promoting nutrition-related education was aimed at balancing the energy and nutrient contents. Schizophrenia patients were shown to be capable of accepting and observing the principles of appropriate nutrition. The intervention was strong enough to result in a significant blood glucose concentration drop to the reference level in all patients, regardless of the antipsychotic they were treated with. The blood lipid levels also improved, but the reduction in triacylglycerols, total cholesterol and LDL-cholesterol levels was significant in the male patients only. Nutritional changes were reflected in overweight and obese women only, in body weight reduction and in waist adipose tissue loss.

The Intestinal and Skin Microbiome in Patients with Atopic Dermatitis and Their Influence on the Course of the Disease: A Literature Review

Bacteria inhabiting the digestive tract are responsible for our health. The microbiome is essential for the development of the immune system and homeostasis of the body. Maintaining homeostasis is very important, but also extremely complicated. The gut microbiome is related to the skin microbiome. It can therefore be assumed that changes in the microbes inhabiting the skin are greatly influenced by the bacteria living in the intestines. Changes in the composition and function of microbes (dysbiosis in the skin and intestines) have recently been linked to changes in the immune response and the development of skin diseases, including atopic dermatitis (AD). This review was compiled by collaborating Dermatologists specializing in atopic dermatitis and psoriasis. A comprehensive review of the current literature was performed using PubMed and limited to relevant case reports and original papers on the skin microbiome in atopic dermatitis. The inclusion criterion was that the paper was published in a peer-reviewed journal in the last 10 years (2012-2022). No limitations on the language of the publication or the type of study were made. It has been shown that any rapid changes in the composition of the microflora may be associated with the appearance of clinical signs and symptoms of the disease. Various studies have proven that the microbiome of many systems (including the intestines) may have a significant impact on the development of the inflammatory process within the skin in the course of AD. It has been shown that an early interaction between the microbiome and immune system may result in a noticeable delay in the onset of atopic diseases. It seems to be of high importance for physicians to understand the role of the microbiome in AD, not only from the pathophysiological standpoint but also in terms of the complex treatment that is required. Perhaps young children diagnosed with AD present specific characteristics of the intestinal microflora. This might be related to the early introduction of antibiotics and dietary manipulations in breastfeeding mothers in the early childhood of AD patients. It is most likely related to the abuse of antibiotics from the first days of life.

Association between Gut Dysbiosis and the Occurrence of SIBO, LIBO, SIFO and IMO

Gut microbiota is the aggregate of all microorganisms in the human digestive system. There are 1014 CFU/mL of such microorganisms in the human body, including bacteria, viruses, fungi, archaea and protozoa. The Firmicutes and Bacteroidetes bacteria phyla comprise 90% of the human gut microbiota. The microbiota support the healthy functioning of the human body by helping with digestion (mainly via short-chain fatty acids and amino acids) and producing short-chain fatty acids. In addition, it exhibits many physiological functions, such as forming the intestinal epithelium, intestinal integrity maintenance, the production of vitamins, and protection against pathogens. An altered composition or the number of microorganisms, known as dysbiosis, disrupts the body's homeostasis and can lead to the development of inflammatory bowel disease, irritable bowel syndrome, and metabolic diseases such as diabetes, obesity and allergies. Several types of disruptions to the gut microbiota have been identified: SIBO (Small Intestinal Bacterial Overgrowth), LIBO (Large Intestinal Bacterial Overgrowth), SIFO (Small Intestinal Fungal Overgrowth), and IMO (Intestinal Methanogen Overgrowth). General gastrointestinal problems such as abdominal pain, bloating, gas, diarrhoea and constipation are the main symptoms of dysbiosis. They lead to malabsorption, nutrient deficiencies, anaemia and hypoproteinaemia. Increased lipopolysaccharide (LPS) permeability, stimulating the inflammatory response and resulting in chronic inflammation, has been identified as the leading cause of microbial overgrowth in the gut. The subject literature is extensive but of limited quality. Despite the recent interest in the gut microbiome and its disorders, more clinical research is needed to determine the pathophysiology, effective treatments, and prevention of small and large intestinal microbiota overgrowth. This review was designed to provide an overview of the available literature on intestinal microbial dysbiosis (SIBO, LIBO, SIFO and IMO) and to determine whether it represents a real threat to human health.

Effects of a Diet Containing Sources of Prebiotics and Probiotics and Modification of the Gut Microbiota on the Reduction of Body Fat

In 2022, according to the World Health Organization (WHO) report, overweight and obesity have reached epidemic proportions in the WHO European Region, affecting almost 60% of adults. Based on the assessment of BMI (Body Mass Index), a group of 56 women aged 25-45 years (31 women group A average BMI 34.9 ± 4.86 kg/m2 and 25 women group B average BMI 33.4 ± 4.02 kg/m2) were qualified for the study. In a multi-center, two-arm, parallel, non-randomized study, two types of weight-reduction diets (A and B) were used over a 3-month period. In group A, a standard low-energy diet was used with individually adjusted caloric intake of 1100-1300 kcal, with an increase in the amount and frequency of consumption of sauerkraut and groats and a daily intake of fermented milk drinks (300-400 g), fermented cucumbers (100 g), mineral water (1 L) and cod liver oil (5 mL). In group B, a standard low-energy diet with individually adjusted caloric intake of 1100-1300 kcal with daily intake of fermented milk products (150 g), highly mineralized water (0.5 L), once a week fermented cucumbers, and once a week buckwheat groats was used. The following measurements were taken: body weight, body fat mass, water content, body height, waist circumference, and hip circumference. Body weight and body composition were measured using the Tanita MC-780 MA and TANITA BC-601 analyzer using the bioelectric bioimpedance method. The stool samples were analyzed in the microbiology laboratory where quantification of Bifidobcaterium spp., Bacteroides spp., Faecalibacterium prausnitzii species, Akkermansia muciniphila and total bacterial count (TBC) was performed. Under the influence of the introduced nutritional intervention, a statistically significant reduction in body weight, body fat, waist circumference, and hip circumference was demonstrated after 3 months. Under the influence of weight reduction, as well as dietary changes, there was an increase in the number of Akkermansia muciniphila bacteria in the women studied. The low-energy diet containing sources of natural prebiotics and probiotics had a more favorable effect on the number of Faecalibacterium prausnitzii bacteria compared to the standard diet.

Therapeutic efficacy of amoxicillin and rifaximin in patients with small intestinal bacterial overgrowth and Helicobacter pylori infection

Introduction

Small intestinal bacterial overgrowth (SIBO) may coexist with Helicobacter pylori infection, which can be the cause of chronic gastrointestinal complaints.

Aim

Evaluation of the therapeutic efficacy of amoxicillin and rifaximin in the treatment of these diseases.

Material and methods

The lactulose hydrogen breath test (LHBT) and the urea breath test (¹³C-UBT) were performed in 116 patients. In 62 patients the coexistence of small intestinal bacterial overgrowth and H. pylori infection was observed. Then, in group I (n = 30) pantoprazole (2 × 40 mg), amoxicillin (2 × 1000 mg) and metronidazole (2 × 500 mg) and in group II (n = 32) pantoprazole and amoxicillin at the above doses and rifaximin (3 × 400 mg) were administered for 10 days. After 6 weeks, both breath tests were repeated and the degree of remission of symptoms was measured using a 10-point visual analog scale (VAS).

Results

After the treatment the LHBT index decreased in group I from 61.2 ±19.4 ppm to 22.0 ±8.2 ppm (p < 0.001) and in group II from 59.6 ±15.5 ppm to 15.2 ±8.6 ppm (p < 0.001). Eradication of H. pylori (¹³C-UBT below 4.0‰) was achieved in 63.3% of patients in group I and 59.4% in group II (p > 0.05). The decrease of pain below 3.0 points in the VAS was obtained in 64.8% of patients in group I and in 56.2% in group II.

Conclusions

Combination of amoxicillin and rifaximin may be effective in the treatment of patients with small intestinal bacterial overgrowth syndrome and concomitant H. pylori infection.

Changes in intestinal microflora of Caenorhabditis elegans following Bacillus nematocida B16 infection

The effect of pathogenic bacteria on a host and its symbiotic microbiota is vital and widespread in the biotic world. The soil-dwelling opportunistic bacterium Bacillus nematocida B16 uses a "Trojan horse" mechanism to kill Caenorhabditis elegans. The alterations in the intestinal microflora that occur after B16 infection remain unknown. Here, we analyzed the intestinal bacteria presented in normal and infected worms. The gut microbial community experienced a complex change after B16 inoculation, as determined through marked differences in species diversity, structure, distribution and composition between uninfected and infected worms. Regardless of the worm's origin (i.e., from soil or rotten fruits), the diversity of the intestinal microbiome decreased after infection. Firmicutes increased sharply, whereas Proteobacteria, Actinobacteria, Cyanobacteria and Acidobacteria decreased to different degrees. Fusobacteria was only present 12 h post-infection. After 24 h of infection, 1228 and 1109 bacterial species were identified in the uninfected and infected groups, respectively. The shared species reached 21.97%. The infected group had a greater number of Bacillus species but a smaller number of Pediococcus, Halomonas, Escherichia and Shewanella species (P < 0.01). Therefore, this study provides the first evaluation of the alterations caused by pathogenic bacteria on symbiotic microbiota using C. elegans as the model species.

Comparison of feeding habits and physical activity between eutrophic and overweight/obese children and adolescents: a cross sectional study

Summary Objective: it is broadly accepted, but little explored, that obese children practice less physical activity and eat more. This study has the objective of comparing feeding habits and physical activity between eutrophic and overweight/obese children and adolescents. Methods: 126 students with ages ranging from 6 to 18 years were evaluated. Eutrophic and overweight/obese students were compared according to calorie intake, macro and micronutrients, prevalence of physical inactivity and ingestion of micronutrients. Results: differences were observed in the amount of calories ingested per unit of BMI (eutrophic, 97.6, and overweight/obese, 70.5, p=0.0061), as well as in calcium intake (eutrophic, 546.2, and overweight/obese, 440.7, p=0.0366). Both groups presented sedentarism, as well as a high prevalence of micronutrient intake deficiency, especially calcium and vitamins A, E, and C, but with no difference observed between eutrophic and overweight/obese subjects. Conclusion: energy and macronutrients consumption, as well as physical activity, were similar between eutrophic and overweight/obese. Calcium intake was lower in the overweight/obese group and the ingestion of vitamin C was lower in the eutrophic group. These results demonstrate the importance of considering all etiologic factors that may lead to obesity, so that new strategies for prevention and control may be added to traditional interventions.

Anti-obesity activity of the marine carotenoid fucoxanthin

Nowadays the global tendency towards physical activity reduction and an augmented dietary intake of fats, sugars and calories is leading to a growing propagation of overweight, obesity and lifestyle-related diseases, such diabetes, hypertension, dyslipidemia and metabolic syndrome. In particular, obesity, characterized as a state of low-level inflammation, is a powerful determinant both in the development of insulin resistance and in the progression to type 2 diabetes. A few molecular targets offer hope for anti-obesity therapeutics. One of the keys to success could be the induction of uncoupling protein 1 (UCP1) in abdominal white adipose tissue (WAT) and the regulation of cytokine secretions from both abdominal adipose cells and macrophage cells infiltrated into adipose tissue. Anti-obesity effects of fucoxanthin, a characteristic carotenoid, exactly belonging to xanthophylls, have been reported. Nutrigenomic studies reveal that fucoxanthin induces UCP1 in abdominal WAT mitochondria, leading to the oxidation of fatty acids and heat production in WAT. Fucoxanthin improves insulin resistance and decreases blood glucose levels through the regulation of cytokine secretions from WAT. The key structure of anti-obesity effect is suggested to be the carotenoid end of the polyene chromophore, which contains an allenic bond and two hydroxyl groups. Fucoxanthin, which can be isolated from edible brown seaweeds, recently displayed its many physiological functions and biological properties. We reviewed recent studies and this article aims to explain essential background of fucoxanthin, focusing on its promising potential anti-obesity effects. In this respect, fucoxanthin can be developed into promising marine drugs and nutritional products, in order to become a helpful functional food.

Microbiota and metabolome associated with immunoglobulin A nephropathy (IgAN)

This study aimed at investigating the fecal microbiota, and the fecal and urinary metabolome of non progressor (NP) and progressor (P) patients with immunoglobulin A nephropathy (IgAN). Three groups of volunteers were included in the study: (i) sixteen IgAN NP patients; (ii) sixteen IgAN P patients; and (iii) sixteen healthy control (HC) subjects, without known diseases. Selective media were used to determine the main cultivable bacterial groups. Bacterial tag-encoded FLX-titanium amplicon pyrosequencing of the 16S rDNA and 16S rRNA was carried out to determine total and metabolically active bacteria, respectively. Biochrom 30 series amino acid analyzer and gas-chromatography mass spectrometry/solid-phase microextraction (GC-MS/SPME) analyses were mainly carried out for metabolomic analyses. As estimated by rarefaction, Chao and Shannon diversity index, the lowest microbial diversity was found in P patients. Firmicutes increased in the fecal samples of NP and, especially, P patients due to the higher percentages of some genera/species of Ruminococcaceae, Lachnospiraceae, Eubacteriaceae and Streptococcaeae. With a few exceptions, species of Clostridium, Enterococcus and Lactobacillus genera were found at the highest levels in HC. Bacteroidaceae, Porphyromonadaceae, Prevotellaceae and Rikenellaceae families differed among NP, P and HC subjects. Sutterellaceae and Enterobacteriaceae species were almost the highest in the fecal samples of NP and/or P patients. Compared to HC subjects, Bifidobacterium species decreased in the fecal samples of NP and P. As shown by multivariate statistical analyses, the levels of metabolites (free amino acids and organic volatile compounds) from fecal and urinary samples markedly differentiated NP and, especially, P patients.

Changes in intestinal microflora in rats with acute respiratory distress syndrome

AIM

To implement high-throughput 16S rDNA sequencing to study microbial diversity in the fecal matter of rats with acute lung injury/acute respiratory distress syndrome (ALI/ARDS).

METHODS

Intratracheal instillation of lipopolysaccharide was used to induce ALI, and the pathological changes in the lungs and intestines were observed. D-lactate levels and diamine oxidase (DAO) activities were determined by enzymatic spectrophotometry. The fragments encompassing V4 16S rDNA hypervariable regions were PCR amplified from fecal samples, and the PCR products of V4 were sequenced by Illumina MiSeq.

RESULTS

Increased D-lactate levels and DAO activities were observed in the model group (P < 0.01). Sequencing results revealed the presence of 3780 and 4142 species in the control and model groups, respectively. The percentage of shared species was 18.8419%. Compared with the control group, the model group had a higher diversity index and a lower number of species of Fusobacteria (at the phylum level), Helicobacter and Roseburia (at the genus level) (P < 0.01). Differences in species diversity, structure, distribution and composition were found between the control group and early ARDS group.

CONCLUSION

The detection of specific bacteria allows early detection and diagnosis of ALI/ARDS.

Impact of the gut microbiota on the development of obesity and type 2 diabetes mellitus

Obesity and its associated disorders are a major public health concern. Although obesity has been mainly related with perturbations of the balance between food intake and energy expenditure, other factors must nevertheless be considered. Recent insight suggests that an altered composition and diversity of gut microbiota could play an important role in the development of metabolic disorders. This review discusses research aimed at understanding the role of gut microbiota in the pathogenesis of obesity and type 2 diabetes mellitus (TDM2). The establishment of gut microbiota is dependent on the type of birth. With effect from this point, gut microbiota remain quite stable, although changes take place between birth and adulthood due to external influences, such as diet, disease and environment. Understand these changes is important to predict diseases and develop therapies. A new theory suggests that gut microbiota contribute to the regulation of energy homeostasis, provoking the development of an impairment in energy homeostasis and causing metabolic diseases, such as insulin resistance or TDM2. The metabolic endotoxemia, modifications in the secretion of incretins and butyrate production might explain the influence of the microbiota in these diseases.

Modulation of gut microbiota in the management of metabolic disorders: the prospects and challenges

The gut microbiota plays a number of important roles including digestion, metabolism, extraction of nutrients, synthesis of vitamins, prevention against pathogen colonization, and modulation of the immune system. Alterations or changes in composition and biodiversity of the gut microbiota have been associated with many gastrointestinal tract (GIT) disorders such as inflammatory bowel disease and colon cancer. Recent evidence suggests that altered composition and diversity of gut microbiota may play a role in the increased prevalence of metabolic diseases. This review article has two main objectives. First, it underscores approaches (such as probiotics, prebiotics, antimicrobial agents, bariatric surgery, and weight loss strategies) and their prospects in modulating the gut microbiota in the management of metabolic diseases. Second, it highlights some of the current challenges and discusses areas of future research as it relates to the gut microbiota and metabolic diseases. The prospect of modulating the gut microbiota seems promising. However, considering that research investigating the role of gut microbiota in metabolic diseases is still in its infancy, more rigorous and well-designed in vitro, animal and clinical studies are needed.