Efficacy of very low calorie diet in the intervention of obesity and the changes in oral microbiota: a prospective cohort study.

VLCD intervention induced rapid, clinically meaningful reductions in body weight, body fat mass, BMI, and visceral fat area in obese adults.

• Per-protocol cohort included n=101 overweight/obese individuals
• Study conducted at Affiliated Hospital of Hubei University of Chinese Medicine, concluded December 31, 2023
• Reductions in body weight, body fat mass (BFM), body mass index (BMI), and visceral fat area (VFA) were described as 'rapid' and 'clinically meaningful'
• Skeletal muscle mass (SMM) decreased modestly during the intervention

VLCD intervention significantly improved metabolic parameters including fasting blood glucose, fasting insulin, and insulin resistance.

• Fasting blood glucose (FBG) decreased significantly post-intervention
• Fasting insulin (FIns) decreased significantly post-intervention
• Homeostasis model assessment of insulin resistance (HOMA-IR) decreased significantly
• These improvements were observed in the per-protocol cohort of n=101 participants

Lipid profiles showed transient increases in LDL-C and total cholesterol at day 5 of VLCD, which normalized by the two-week follow-up.

• Low-density lipoprotein cholesterol (LDL-C) transiently increased at day 5
• Total cholesterol (CHOL) transiently increased at day 5
• Both LDL-C and CHOL normalized by the two-week follow-up period
• Triglycerides (TG) were reduced during the intervention

Systemic inflammation markers declined after resuming normal diet following VLCD intervention.

• Alanine aminotransferase (ALT) declined after resuming normal diet
• High-sensitivity C-reactive protein (hs-CRP) declined after resuming normal diet
• Uric acid (UA) peaked transiently during the VLCD before falling below baseline
• These changes suggest potential for reducing inflammation-related comorbidities

VLCD intervention altered tongue-coating microbiota, increasing Shannon diversity and shifting community structure.

• Shannon diversity index increased in tongue-coating microbiota following VLCD
• Community structure of oral microbiota shifted post-intervention
• 12 reduced species were identified and associated with 19 systemic diseases
• The study specifically analyzed microbiota of the upper gastrointestinal tract via oral coating (tongue coating)

The study design was a prospective cohort study with patient eligibility based on adoption of complete short-term VLCD therapy.

• Registered in Chinese Clinical Trial Registry (No. ChiCTR2200063126, registered August 31, 2022)
• Study concluded December 31, 2023
• Per-protocol cohort consisted of n=101 participants
• Inclusion criterion was completion of a full short-term VLCD therapy following cohort entry
• Participants were overweight/obese individuals