A Chinese medical nutrition therapy diet accompanied by intermittent energy restriction alleviates type 2 diabetes by enhancing pancreatic islet function and regulating gut microbiota composition

Abstract

Medicine food homologous (MFH) plants and wholegrains have gained increasing attention for prevention and treatment of type 2 diabetes (T2D). Substantial evidence supports the effectiveness of intermittent energy restriction (IER) in T2D management. However, there are few studies that report intermittent use of a low-calorie pre-prepared food including MFH plants and wholegrains in T2D. The aim of this study was to investigate the effects of Chinese Medical Nutrition Therapy (CMNT), a MFH plants and wholegrains diet accompanied by IER, on glycemic control and potential mechanism. Ten-week-old diabetic db/db mice were randomly divided into CMNT group (feeding low-calorie mouse CMNT diet in day 1–4 and ad libitum regular chow for up to 7 days per cycle) and control group (ad libitum access to regular chow). The results showed that CMNT reduced fasting blood glucose, improved glucose tolerance with higher insulin secretion, attenuated macrophage infiltration, promoted β-cell proliferation of pancreatic islets, and increased diabetes-improving microbiota (Bacteroides, Rikenellaceae_RC9_gut_group and Coprococcus_1) in db/db mice. Additionally, we performed a pilot study evaluating CMNT in thirty-nine T2D patients without obesity. Participants with T2D randomly assigned to two groups: CMNT group (receiving a consecutive 5-day low-calorie human CMNT diet with 10 days of habitual eating per cycle for 90 days) and control group (continuing on a normal diet). We observed an improvement in glycemic control in CMNT group with significant reduction in HbA1c, fasting glucose, 2 h postprandial blood glucose but control group were not affected. After CMNT intervention, the abundance of the phylum Bacteroidetes, and genus Bacteroides, Parabacteroides and Roseburia were significantly higher than baseline in T2D patient, which were closely associated with glycemic control. These findings suggested that CMNT is a promising nutritional intervention approach in diabetes management.