The Effect of Probiotics and Calcium Supplementation During Childhood on Hemoglobin Level and Anemia Prevalence: A 10-Year Follow-Up Study

Objectives: Some probiotics may enhance iron absorption and reduce the risk of anemia. We investigated the effect of probiotics and calcium supplementation during childhood on hemoglobin levels and anemia in adolescents 10 years later. Methods: This study was a follow-up of a double-blind randomized controlled trial conducted in 2007-2008 involving 494 children aged 1-6 years old living in Jakarta, Indonesia. We re-enrolled 238 adolescents who had previously received twice-daily low-lactose milk for 6 months with the content of either: (1) low-calcium (LC, ∼50 mg/day, n=53/124), (2) regular-calcium (RC, ∼440 mg/day, n=70/126), (3) RC with 5x108 CFU/d of Lactobacillus casei CRL431 (casei, n=60/120) or (4) RC with 5x108 CFU/d of L. reuteri DSM17938 (reuteri, n=55/124). Hemoglobin (Hb) levels were measured in venous blood using HemoCue 201 and adjusted for smoking status. We used age- and sex-dependent WHO criteria to determine anemia. Linear and logistic regressions with post-hoc pairwise comparisons were used to evaluate the effect of the interventions. Results: Baseline characteristics among the 238 found and 256 unfound adolescents across intervention groups were similar. Mean age at follow-up was ∼15 yo, and female were 53% of LC, 51% of RC, 45% of casei, and 64% of reuteri. Mean Hb levels were 13.1±2.1 g/dl in LC, 13.1±2.1 g/dl in RC, 13.9±1.9 g/dl in casei, and 13.2±2.3 g/dl in reuteri. The casei group had a significantly 0.74 g/dl higher Hb than RC (95%CI 0.01–1.47; p=0.047). Anemia prevalence ranged from 20% (casei), 26% (reuteri), 29% (RC), to 32% (LC), but the differences were not significant across treatment. Conclusions: Probiotic L. casei CRL431 supplementation with regular calcium during childhood demonstrated higher Hb levels 10 years later among adolescents than regular calcium alone. We observed large differences, but not significant, in anemia prevalence. Large effectiveness studies exploring probiotic strains beneficial for reducing anemia during the sensitive period of gut microbiota development are warranted. Funding Sources: Ministry of Research, Technology, and Higher Education of the Republic of Indonesia; Directorate of Research and Community Engagement, Universitas Indonesia; Indonesian Endowment Fund for Education (LPDP) and Tops Institute for Food and Nutrition, The Netherlands.