PP406 - GUT BIDIRECTIONAL AMINO ACID EXCHANGE IN ZAMBIAN ADULTS WITH ENVIRONMENTAL ENTEROPATHY

PP406

GUT BIDIRECTIONAL AMINO ACID EXCHANGE IN ZAMBIAN ADULTS WITH ENVIRONMENTAL ENTEROPATHY

M. Jain^1,*, J. Weatherill¹, E. Mckay¹, P. Kelly^2,3, D. J. Morrison¹

¹SUERC, University of Glasgow, Glasgow, ²Queen Mary University, London, United Kingdom, ³TROPGAN, Lusaka, Zambia

Rationale: Environmental enteropathy (EE) is linked to impaired nutrient absorption and adverse clinical outcomes in low- and middle-income settings. We investigated the relationship between intestinal permeability and bidirectional transmucosal amino acid flux (BTAAF) in Zambian adults.

Methods: We recruited 80 participants from a low socio-economic status (L-SES) setting (Misisi, Lusaka) where EE is highly prevalent and 16 participants from high socio-economic status (H-SES) as controls. Fasted participants received a primed (0.6 µmol/kg) pseudo-constant oral dose of ¹³C₆-phenylalanine (0.15 µmol/kg) every 20 mins and primed (0.6 µmol/kg) constant intravenous infusion of ²H₅-phenylalanine (0.15 µmol/kg) for 240 mins. Plasma samples were collected serially, and a single intestinal aspirate was obtained during duodenal endoscopy at 240 mins. Indispensable amino acids (IAAs) were purified and analysed by LC-MS. Uptake of amino acids (BTAAF_in) was calculated by plateau ¹³C₆-Phe/²H₅-Phe in plasma and efflux from plasma to intestine (BTAAF_out) was calculated by the ratio of intestinal ²H₅-Phe/Phe relative to plasma ²H₅-Phe/Phe. L-SES was compared with H-SES by Mann-Whitney U test.

Results: Figure 1 shows that BTAAF_in was significantly lower in the L-SES group compared with H-SES group (median [IQR]: 0.70 [0.57, 0.99] vs 1.23 [1.00, 1.60], p<0.001). There were no significant differences in BTAAF_out between the groups (L-SES: 1.40 [0.59, 2.42] vs H-SES: 1.38 [0.97, 1.81], p=0.37) although surprisingly, efflux of IAAs into the intestine occurred in almost all participants with greater variability in the L-SES group.

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Conclusion: The bidirectional flow of IAAs appears to be a normal phenomenon; however, participants in the L-SES group have significantly lower BTAAF_in compared with H-SES. In individuals where BTAAF_out is greater than BTAAF_in, this may indicate net IAA loss with potential implications for higher protein requirements.

Disclosure of Interest: None declared