Effects of short-term very low-calorie restriction on gut microbiota in overweight/obese patients with type 2 diabetes / 中华内分泌代谢杂志

ABSTRACT

Objective:To evaluate the effect of short-term very low-calorie restriction(VLCR) on glycemic control in overweight/obese patients with type 2 diabetes, and to explore mechanisms through identifying markers of gut microbiota.Methods:This trial was conducted in 14 adult overweight/obese patients with type 2 diabetes. They received VLCR for 9 days in the hospital(calorie intake 300-600 kcal/d). Before and after VLCR, body weight(BW), waist circumference(WC), blood pressure(BP), and heart rate(HR) were measured, and body mass index(BMI) was calculated according to their height and weight. Fasting blood glucose(FBG), 2 h postprandial blood glucose(2hPBG), fasting insulin(FINS), triglycerides(TG), total cholesterol(TC), high-density lipoprotein-cholesterol(HDL-C), and low-density lipoprotein-cholesterol(LDL-C) were determined, and yielded the homeostasis model assessment for insulin resistance(HOMA-IR). Additional lab tests such as liver and kidney function and electrolytes were performed. The estimated glomerular filtration rate(eGFR) was calculated to evaluate renal function. All data were analyzed using the SPSS Sample Power software. Feces samples were collected before and after VLCR. Fecal samples were tested for microbial diversity using 16S rDNA technology. Professional software was used to analyze the differences of gut microbiota in feces before and after VLCR.Results:After 9 days of VLCR, BW, BMI, WC, BP, HR, FBG, 2hPBG, FINS, HOMA-IR, alkaline phosphatase, TG, and blood urea nitrogen of 14 overweight/obese patients with type 2 diabetes were significantly reduced( P<0.05). No effect was seen on serum alanine aminotransferase, aspartate amino transferase, gamma glutamyl transferase, TC, HDL-C, LDL-C, creatinine, eGFR, uric acid, albumin, calcium, and phosphorus( P>0.05). The gut microbiota diversity did not differ before and after VLCR. The abundance of Bacteroidetes increased significantly, and the Firmicutes/Bacteroidetes ratio decreased from 11.79 to 4.20. Between groups analysis showed the abundance of Parabacteroides distasonis increased significantly after VLCR. Conclusion:VLCR can improve body weight and glucose and lipid metabolism in overweight/obese patients with type 2 diabetes, with no serious adverse events. Parabacteroides distasonis may be a marker of VLCR.