Development Sangyod rice protein-based formula for cow milk allergic infant and its gut microbiota modulation

Background: In Thailand, cow milk allergies are the leading food allergy in infants. Rice protein is one of the hypoallergenic food ingredients used as an alternative plant-based protein in nutritional products. Sangyod rice (Oryza sativa, L., var. indica), found in southern Thailand, has been reported to contain a high content of nutrients. Isomaltooligosaccharides (IMO) are accepted as prebiotics and are applicable as food ingredients to enhance the physiochemical quality of foods as a sweetener, and can also have physiological functions including the enhancement of gut microflora. The supplementation of formulas with prebiotics will support a mature immune system and intestinal colonization of infants. Objectives: This research aimed to develop Sangyod rice protein-based infant formula for cow milk allergic infants, evaluated its nutritional composition, sensory, and anti-allergenic activity, and investigated the effects of the formula on gut microbiota modulation. Materials and methods: The development of infant formula based on Sangyod rice protein and fortified with IMO from Sangyod rice flour was studied on nutrition composition, microbiology, anti-allergenic activity, and effect on gut microbiota. These properties reflect quality and safety to meet requirements of infant and follow-up formula. Results: The energy of Sangyod rice-protein-based formula was 67 kcal per 100 ml. The results indicated that the formula met the requirements of macronutrients providing 3.03 g of protein, 4.37 g of fat, and 13.26 g of carbohydrate, and passed on total bacteria contamination. Surprisingly, the developed formulas showed higher results in an anti-allergenic activity test (86.98 +/- 5.49%) by inhibition on the release of beta-hexosaminidase enzyme in RBL-2H3 cells compared to a commercial hypoallergenic formula. The addition of prebiotic (IMO) significantly increased populations of Lactobacillus (10.7 log cell/ml) within 24 hours (p<0.05) compared with commercial product. This result affected the production of shot chain fatty acids (SCFAs) by increasing the amount of acetic acid and propionic acid, but had no effect on lactic acid and butyric acid production. This result may have a beneficial effect on the immune system and hopefully can help to prevent or decrease risk of cow milk allergy. The sensory evaluation of Sangyod rice protein-based formula showed the highest scores in test (6.34 +/- 1.39), odor (6.74 +/- 1.15) and overall acceptability (6.52 +/- 1.26), but had no significant differences (p<0.05) compared to commercial hypoallergenic formula. Conclusion: The Sangyod rice protein-based formula can compete and was acceptable for the hypoallergenic formula and would be an option for substituting cow milk in the treatment of cow milk protein allergy. However, this study is the first step to develop the hypoallergenic formula and still needs the preclinical testing and clinical study in the future to claim as a hypoallergenic formula.