Carbohydrates serve as important energy sources and structural substances for human body as well as for gut microbes. As evidenced by the advances in immunometabolism, glucose metabolism and adenosine triphosphate (ATP) generation are deeply involved in immune cell activation, proliferation, and signaling transduction as well as trafficking and effector functions, thus contributing to immune response programming and assisting in host adaption to microenvironment changes. Increased glucose uptake, aberrant expression of glucose transporter 1 (e.g., GLU1), and abnormal glycosylation patterns have been identified in autoimmunity and are suggested as partially responsible for the dysregulated immune response and the modification of gut microbiome composition in the autoimmune pathogenesis. The interaction between gut microbiota and host carbohydrate metabolism is complex and bidirectional. Their impact on host immune homeostasis and the development of autoimmune diseases remains to be elucidated. This review summarized the current knowledge on the crosstalk of glucose metabolism and glycosylation in the host with intestinal microbiota and discussed their possible role in the development and progression of autoimmune diseases. Potential therapeutic strategies targeting glucose metabolism and glycosylation in modulating gut ecosystem and treating autoimmune diseases were discussed as well.

Objective To investigate the dietary patterns and lifestyles of patients with lupus gastrointestinal (GI) involvement and to reveal the possible role of organ-specific involvement of systemic lupus erythematosus (SLE) on daily diet. Methods Patients with SLE complicated with gastrointestinal involvement (SLE-GI) admitted to Peking Union Medical College Hospital (PUMCH) from January 2010 to September 2021 were enrolled. Age- and sex-matched SLE patients with lupus nephritis (SLE-LN) but free of other internal organs involvement who were admitted during the same period were enrolled as disease controls at the ratio of 1:1. In addition, a group of age- and sex-matched healthy people were also included as healthy controls (HCs). Questionnaires were distributed to these patients and HC to collect their dietary patterns and lifestyle information. Clinical features, dietary and lifestyle habits were compared between the two groups of patients and HC. Results The questionnaire survey showed that compared with HC, the SLE-GI group had higher proportions of vegetarians ( p = 0.014) and a lower proportion of omnivores ( p = 0.058). A higher percentage of SLE-GI patients reported a traditional Chinese medicine ( p = 0.018) taken history and surgical history ( p = 0.014). They also less likely to take fried/pickled food ( p = 0.042) and dietary supplements ( p = 0.024) than HC. Higher percentages of SLE-GI patients and SLE-LN patients preferred self-catering (87.5% and 94.3%) over take-out food than HC (70.8%) ( p = 0.127 and p = 0.016). No significant difference on drinking preference among the three groups, but it seemed more SLE-GI patients consumed yogurt than HC ( p = 0.097). The SLE-LN patients were also found to have lower frequencies of staying up late ( p = 0.005). The SLE-GI group also presented higher positivity rates for anti-SSA (69.6% vs . 45.7%, p = 0.020) and anti-SSB antibodies (32.6% vs . 10.9%, p = 0.011) but lower positivity rates for anti-dsDNA antibodies (30.4% vs . 82.6%, p < 0.001) compared with the SLE-LN group. Conclusion The dietary patterns, life-styles and autoantibody spectrum of SLE-GI patients differed greatly from those of SLE-LN patients and healthy people. These factors may reflect the influence of disease and organ involvement modes on patients’ daily life and may contribute partly to the systemic involvement in SLE.