[The nutritional status change the effectiveness of a dietary supplement of lactic bacteria on the emerging of respiratory tract diseases in children].

One hundred children 6 to 24 month old, normal or undernourished according to weight for height index, received during three months--autumn to winter--a dietary supplement of live Lactobacillus acidophilus and Lactobacillus Casei, 10(7)-10(8)/ml in fermented milk (LB) or an equivalent amount of fluid milk (L) as control. Children's follow-up was performed as outpatients in the Hospital Posadas (Great Buenos Aires). Episodes of respiratory tract infections were recorded and classified according to severity as: Pneumonia (N); Bronchitis (B), Recurrent Obstructive Bronchitis (BOR) and upper respiratory tract infections (CVAS). 58% of children fitted the study protocol, 22 in the LB and 36 in the L group; 21 were undernourished and 37 presented normal weight/height. No deaths were recorded. Total episodes were 103: 34 in LB and 69 in L, that means a frequency of 1.55 and 1.92 episodes/children respectively. In LB a maximum of 3 episodes/children was recorded, meanwhile the number reached 7 in L (p = 0.0373). Severity was higher in L than LB: 0.06 vs. 0 for N; 0.69 vs. 0.45 for B + BOR and 1.17 vs. 1.09 for CVAS. In the control group frequency of severe pathologies was about twice in undernourished than in normal: 0.08 vs. 0.04 for N; 1.08 vs. 0.50 for B + BOR; no difference was found for CVAS. Live lactobacillus supplement suppressed pneumonia and decreased bronchitis in undernourished as well as in normal. In this study undernutrition not only increased the chance of suffering severe acute respiratory tract infections but also impaired the effectiveness of the supplement to decrease severity. The effect is explained on the basis of the immunocompetence depression linked to an inadequate nutritional status.