Weight Loss and Short-Chain Fatty Acids Reduce Systemic Inflammation in Monocytes and Adipose Tissue Macrophages from Obese Subjects.

Background: Chronic low-grade systemic inflammation is a characteristic of obesity that leads to various non-communicable diseases. Weight loss and SCFAs are potential strategies for attenuating obese systemic inflammation.
Methods: Blood samples were collected from 43 obese subjects (BMI ≥ 30 kg/m ² ) scheduled for laparoscopic bariatric sleeve surgery, 26 obese subjects at follow-up 12-18 months post-surgery and 8 healthy weight subjects (BMI 18.5-24.9 kg/m ² ). Monocytes were isolated from blood and adipose tissue macrophages from visceral adipose tissue of obese subjects only. Isolated cells stimulated with 1 ng/mL LPS and treated simultaneously with 300 mM of sodium acetate or 30 mM of sodium propionate or butyrate and supernatant were harvested after 15 h incubation. TNF-α and IL-6 cytokines were measured via ELISA and mRNA gene expression of FFAR2 and FFAR3 , HDAC1 , HDAC2 and HDAC9 , RELA and NFKB1 and MAPK1 via RT-qPCR.
Results: TNF-α and IL-6 production and NFKB1 and RELA mRNA expression were significantly decreased in follow-up subjects compared to baseline. SCFAs significantly reduced TNF-α and IL-6 and altered FFAR and HDAC mRNA expression in monocytes and macrophages from obese subjects.
Conclusion: Weight loss and ex vivo SCFA treatments were successful in combatting systemic inflammation in obesity. Results highlighted molecular changes that occur with weight loss and as a result of SCFA treatment.