Antimicrobial peptides represent an important component of the innate
immune defenses of living organisms, including humans. They are
broad-spectrum surface-acting agents secreted by the epithelial cells
of the body in response to infection. Recently, L-isoleucine and its
analogues have been found to induce antimicrobial peptides. The
objectives of the study were to examine if addition of L-isoleucine to
oral rehydration salts (ORS) solution would reduce stool output and/or
duration of acute diarrhoea in children and induce antimicrobial
peptides in intestine. This double-blind randomized controlled trial
was conducted at the Dhaka Hospital of ICDDR,B. Fifty male children,
aged 6-36 months, with acute diarrhoea and some dehydration, attending
the hospital, were included in the study. Twenty-five children received
L-isoleucine (2 g/L)-added ORS (study), and 25 received ORS without
L-isoleucine (control). Stool weight, ORS intake, and duration of
diarrhoea were the primary outcomes. There was a trend in reduction in
mean\ub1standard deviation (SD) daily stool output (g) of children in
the L-isoleucine group from day 2 but it was significant on day 3
(388\ub1261 vs 653\ub1446; the difference between mean [95%
confidence interval (CI) (-)265 (-509, -20); p=0.035]. Although the
cumulative stool output from day 1 to day 3 reduced by 26% in the
isoleucine group, it was not significant. Also, there was a trend in
reduction in the mean\ub1SD intake of ORS solution (mL) in the
L-isoleucine group but it was significant only on day 1 (410\ub1169
vs 564\ub1301), the difference between mean (95% CI) (-)154 (-288,
-18); p=0.04. The duration (hours) of diarrhoea was similar in both the
groups. A gradual increase in stool concentrations of
f-defensin 2
and 3 was noted but they were not significantly different between the
groups. L-isoleucine-supplemented ORS might be beneficial in reducing
stool output and ORS intake in children with acute watery diarrhoea. A
further study is warranted to substantiate the therapeutic effect of
L-isoleucine