Influence of taste and smell perception on weight loss induced by sleeve gastrectomy and its association with gut microbiota.

Background: Eating behavior has been suggested to be influenced by the interplay between chemosensory perception and gut microbiota. Although both factors have been suggested to be altered in obesity and modified by bariatric surgery, there is little evidence about the influence of preoperative smell and taste perception on weight loss outcomes following bariatric surgery, as well as their association with gut microbiota.

Objectives: To assess the predictive role of smell and taste perception in weight loss trajectory after sleeve gastrectomy.

Setting: Vithas Santa Catalina Hospital in Las Palmas, Spain.

Methods: This study included 35 patients who underwent sleeve gastrectomy. Smell and taste assessments and gut microbiota composition analysis were performed before bariatric surgery and 18 months postsurgery. Patients were classified according to the 50th percentile (50P) of the total taste score and olfactory Threshold-Discrimination-Identification (TDI) score.

Results: Patients with TDI>50P showed significantly higher percentage of excess weight loss (%EWL) (P = .035) and their gut microbiota was enriched in Flavonifractor, Ruminococcaceae (genus Incertae Sedis), Eggerthella, Sellimonas, and GCA-900,066,575, whilst patients with TDI<50P showed an enrichment in Eubacterium ruminantium group and Lachnospiraceae UCG-001. %EWL was significantly higher in patients with total taste score >50P (P = .049) and their microbiota were enriched in Sutterellaceae, Barnesiellaceae, Roseburia, Lachnospiraceae_UCG-004, Bilophila, Bilophila wadsworthia, Monoglobaceae and Monoglobus, whilst patients with total taste score <50P showed an enrichment in Lactobacillaceae, Lactobacillus, Klebsiella, Klebsiella pneumoniae, and Streptococcus parasanguinis.

Conclusions: Chemosensory perception could play a role in weight loss trajectory after sleeve gastrectomy through the microbiota-gut-brain axis.