Gut dysbiosis has been linked to type 1 diabetes (T1D); however, microbial capacity in T1D remains unclear. Here, we integratively profiled gut microbial functional and metabolic alterations in children with new-onset T1D in independent cohorts and investigated the underlying mechanisms. In T1D, the microbiota was characterized by decreased butyrate production and bile acid metabolism and increased lipopolysaccharide biosynthesis at the species, gene, and metabolite levels. The combination of 18 bacterial species and fecal metabolites provided excellently discriminatory power for T1D. Gut microbiota from children with T1D induced elevated fasting glucose levels and declined insulin sensitivity in antibiotic-treated mice. In streptozotocin-induced T1D mice, butyrate and lipopolysaccharide exerted protective and destructive effects on islet structure and function, respectively. Lipopolysaccharide aggravated the pancreatic inflammatory response, while butyrate activated Insulin1 and Insulin2 gene expression. Our study revealed perturbed microbial functional and metabolic traits in T1D, providing potential avenues for microbiome-based prevention and intervention for T1D.

Background and Aim The relationship between the oral microbiota and type 1 diabetes (T1D) remains unclear. We aimed to evaluate the variations in the oral microbiome in T1D and identify potentially associated bacterial factors. Methods We performed high-throughput sequencing of the V3-V4 area of the 16S rRNA gene to profile the oral bacterial composition of 47 healthy children (CON group), 46 children with new-onset T1D in the acute phase (NT1D group), and 10 children with T1D in the chronic phase receiving insulin treatment (CT1D group). Multivariate statistical analysis of sequencing data was performed. Results Compared to the CON group, the NT1D group was characterized by decreased diversity and increased abundance of genera harboring opportunistic pathogens, while this trend was partially reversed in the CT1D group. Differential genera between groups could distinguish the NT1D group from the CON group (AUC = 0.933) and CT1D group (AUC = 0.846), respectively. Moreover, T1D-enriched genera were closely correlated with HbA1c, FBG and WBCs levels. Conclusion Our results showed that the acute phase of T1D was characterized by oral microbiota dysbiosis, which could be partially ameliorated via glycemic control. The possible role of oral microbiota dysbiosis on oral health and systemic metabolic status in T1D warrants further mechanistic investigation.

Background The real-world exposure levels of non-therapeutic antibiotics and neonicotinoids in type 1 diabetes (T1D) children and their associations as environmental triggers through gut microbiota shifts remained unknown. We thus investigated the antibiotics and neonicotinoids’ exposure levels and their associations with gut microbiota in pediatric T1D. Methods Fifty-one newly onset T1D children along with 67 age-matched healthy controls were recruited. Urine concentrations of 28 antibiotics and 12 neonicotinoids were measured by mass spectrometry. Children were grouped according to the kinds of antibiotics’ and neonicotinoids’ exposures, respectively. The 16S rRNA of fecal gut microbiota was sequenced, and the correlation with urine antibiotics and neonicotinoids’ concentrations was analyzed. Results The overall detection rates of antibiotics were 72.5% and 61.2% among T1D and healthy children, whereas the neonicotinoids detection rates were 70.6% and 52.2% (P = 0.044). Children exposed to one kind of antibiotic or two or more kinds of neonicotinoids had higher risk of T1D, with the odd ratios of 2.579 and 3.911. Furthermore, co-exposure to antibiotics and neonicotinoids was associated with T1D, with the odd ratio of 4.924. Antibiotics or neonicotinoids exposure did not affect overall richness and diversity of gut microbiota. However, children who were exposed to neither antibiotics nor neonicotinoids had higher abundance of Lachnospiraceae than children who were exposed to antibiotics and neonicotinoids alone or together. Conclusion High antibiotics and neonicotinoids exposures were found in T1D children, and they were associated with changes in gut microbiota featured with lower abundance of butyrate-producing genera, which might increase the risk of T1D.