Prevalence of methanogens and associated factors in patients with irritable bowel syndrome and healthy controls in a Southeastern Mexican population.

INTRODUCTION: Methane (CH4) is an inert gas produced by colonic anaerobes and has been associated with different intestinal diseases, including irritable bowel syndrome (IBS). According to geographic region, the prevalence of methanogens varies, being higher in Africa (80%) and lower in the United States (35-40%). In Mexico, the prevalence of methanogens is unknown. AIM: To evaluate the prevalence of CH4 producers and associated factors in a group of patients with IBS and controls in a Mexican population. MATERIALS AND METHODS: A baseline fasting measurement of alveolar H2 and CH4 gas was carried out, by gas chromatography (stationary phase), in consecutive patients diagnosed with IBS and a control group. Subjects with baseline levels of H2 of 0 ppm and CH4 ≥ 5 ppm were classified as methanogenic. RESULTS: A total of 132 controls (53.8% women) and 67 patients with IBS (76% women) were included. The overall prevalence (n = 199) of methanogenic subjects was 38% (n = 76) (95% CI: 0.31-0.45) and they had a greater prevalence of overweight/obesity (56.5 vs 39.8%, P = .028). The prevalence of methanogens in the healthy controls was 41.6% (95% CI: 0.33-0.49), whereas, in the patients with IBS, it was 31.4% (n = 21, 71% IBS-C and 29% IBS-M). CONCLUSIONS: The prevalence of methanogens in our study on a Mexican population was comparable to that reported in other populations and was associated with overweight/obesity. One-third of the patients with IBS presented with methanogens. Said microorganisms were particularlyassociated with the constipation-predominant IBS subtype.

Fecal bacterial microbiota in constipated patients before and after eight weeks of daily Bifidobacterium infantis 35624 administration.

INTRODUCTION AND AIM: In recent years, probiotics have been used in functional gastrointestinal disorders, including chronic constipation (CC). The effect of Bifidobacterium infantis strain 35624 on the gut microbiota of CC patients has not been previously studied. Our aim was to analyze the fecal microbiota of constipated patients, before and after consuming a single-strain probiotic (B. infantis strain 35624). MATERIALS AND METHODS: We used 16S rRNA gene high-throughput sequencing to analyze the fecal microbiota of female patients (n=13) with CC. Patients were instructed to ingest one capsule of Alflorex® (containing 1×109 CFUs/g B. infantis strain 35624) daily for eight weeks. Fecal samples were obtained at the baseline and end (final) of probiotic administration. RESULTS: Alpha diversity metrics did not differ between the baseline and final periods. The butyrate producer, Oscillospira, was the taxon most strongly correlated with amplicon sequence variants (R2=0.55, p<0.0001). Except for a few bacterial taxa, there were no significant differences in relative abundance between the baseline and final periods. Beta-diversity measures also showed limited evidence for the differences between the two time periods. CONCLUSIONS: The results suggest that the fecal bacterial microbiota remains stable in constipated women consuming a single-strain probiotic. Those findings may be helpful in better understanding probiotic functioning in patients with digestive disorders.

Bacillus spp. characterization and his intervention as a possible non-traditional etiology of chronic renal insufficiency in Tierra Blanca, Veracruz, Mexico.

Environmental, socioeconomic, educational, custom, occupation, and native pathogen microbiota factors have been identified as unique etiological factors by region for chronic renal insufficiency (CRI). In the region of Tierra Blanca, Veracruz, there is a significant incidence of CRI. The objective of this research was to identify the presence of the genus Bacillus spp. and its kinetic characterization for recognition as a possible non-traditional etiology of CRI in the region. The methodology included the isolation and morphological, biochemical, molecular and kinetic characterization of strains of the genus Bacillus spp. and an analysis of factors that indicate that their presence could affect the occupational health of the population, prompting cases of CRI. The presence of Bacillus cereus (pathogenic strain for humans) was established (biochemical identification, similarity 99%, by 16S rRNA gene) in sugarcane crops, mainly in the MEX-69-290 variety, with the higher growth rate and lower lag phase, compared to the other isolates. The strains are reported as a potential danger of direct infection and a risk factor for the indirect development of CRI, in the non-traditional cause modality, in the sugarcane fields. It is recommended that committed actions be undertaken to protect and promote the health of the population.