Probiotics and prebiotics for SAM in Malawi

A mother receives her child's supply of RUTF

Summary of research¹

A recent study set out to assess the clinical and nutritional efficacy of a probiotic and prebiotic functional food for the treatment of severe acute malnutrition in a HIV-prevalent setting. The rationale for the study was that in some patients, probiotics and prebiotics reduce diarrhoea, promote health gut flora, reduce pathogenic gut bacteria, and directly or indirectly modulate the immune system. Therefore, they should also be beneficial in severe acute malnutrition when impaired gut function is a problem, manifested as diarrhoea and malabsorption, small bowel overgrowth, increased intestinal permeability, enteropathy, gramnegative bacteraemia, and suboptimal immune response.

The study recruited 795 Malawian children (age range 5-168 months) from July 2006 to March 2007, into a double-blind, randomised, placebo-controlled efficacy trial. For generalisability, all admissions for severe acute malnutrition treatment were eligible for recruitment. After stabilisation with milk feeds, children were randomly assigned to ready-to-use therapeutic food either with (n=399) or without (n=396) Synbiotic 2000 Forte. Primary outcome was nutritional cure (weightfor- height >80% of National Centre for Health Statistics median on two consecutive outpatient visits). Secondary outcomes included death, weigh gain, time to cure, and prevalence of clinical symptoms (diarrhoea, fever, and respiratory problems). Analysis was on an intention-to-treat basis.

The study found that nutritional cure was similar in both Synbiotic and control (53.9% [215 of 399] and 51.3% [203 of 396] respectively; p =0.40). Secondary outcomes were also similar between groups. HIV seropositivity was associated with worse outcomes overall, but did not modify or confound the negative results. However, subgroup analyses showed possible trends towards reduced outpatient mortality in the Synbiotic group (p=0.06).

The authors concluded that in Malawi, Synbiotic 2000 Forte did not improve severe acute malnutrition outcomes. It is also concluded that the observation of reduced outpatient mortality might be caused by bias, confounding or chance, but is biologically plausible, has potential for public health impact, and should be explored in future studies.

An editorial comment, 'Addressing severe acute malnutrition where it matters', by Prof Bhutta is available in the same issue, p94.

¹Kerac. M et al (2009). Probiotics and prebiotics for severe acute malnutrition (PRONUT study): a double-blind efficacy randomised controlled trial in Malawi. www.thelancet.com, July 11th 2009, pp 136-145. Open access version at http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(09)60884-9/ab