Nutritional status, serum tryptophan and indole proprionic acid in pulmonary tuberculosis patients

Despite evidence suggesting that Mycobacterium tuberculosis induces tryptophan depletion, microbiota dysbiosis and ultimately immune dysfunction, no data exist on serum levels of tryptophan and microbiota-metabolite (indole proprionic acid, IPA) in Nigerian TB patients. This study determined anthropo-nutritional status [Body Mass Index(BMI), Mid-Upper Arm Circumference(MUAC), Waist Circumference(WC), Hip Circumference(HC)], and Simplified Nutritional Appetite Questionnaire(SNAQ) scores, serum albumin, tryptophan and IPA in Nigerian PTB patients using questionnaire and ELISA as appropriate. Higher prevalence of DS-TB(92%) than MDR-TB(19%) or control(4%) showed appetite loss with a clinically meaningful risk of 5% weight loss within six months. The BMI, MUAC, WC, HC and SNAQ scores were significantly reduced in DS-TB patients or MDR-TB patients compared with control. The MUAC, WC, HC and SNAQ scores were significantly reduced in DS-TB patients compared with MDR-TB patients. The serum levels of albumin were not significantly reduced while the levels of IPA were not significantly increased in DS-TB patients or MDR-TB patients compared with control. The serum levels of tryptophan were significantly increased in DS-TB patients or MDR-TB patients compared with control. Our findings revealed a need for tryptophan-based management for PTB patients and that PTB is an infectious, metabolic and nutritional disease.