Balamurugan Ramadass, Chandragunasekaran Aarthi Sophia, Chellappan Gowri, Rajaram Krithika, Ramamoorthi Gayathri, Ramakrishna Balakrishnan S
The Wellcome Trust Research Laboratory, Department of Gastrointestinal Sciences, Christian Medical College, Vellore, India.
Indian J Med Res. 2014 Sep;140(3):345-55.
BACKGROUND & OBJECTIVES: The human gut microbiota play a significant role in nutritional processes. The concept of probiotics has led to widespread consumption of food preparations containing probiotic microbes such as curd and yogurt. Curd prepared at home is consumed every day in most homes in southern India. In this study the home-made curd was evaluated for lactic acid bacteria (LAB) with probiotic potential.
Fifteen LAB (12 lactobacilli, 1 l0 actococcus , 2 Leuconostoc) and one yeast isolated from home-made curd were evaluated for resistance to acid, pepsin, pancreatin and bile salts; antimicrobial resistance; intrinsic antimicrobial activity; adherence to Caco-2 epithelial cells; ability to block pathogen adherence to Caco-2 cells; ability to inhibit interleukin (IL)-8 secretion from HT-29 epithelial cells in response to Vibrio cholerae; and ability to induce anti-inflammatory cytokine expression in THP-1 monocyte cells.
Lactobacillus abundance in fermenting curd peaked sharply at 12 h. Nine of the strains survived exposure to acid (pH 3.0) for at least one hour, and all strains survived in the presence of pancreatin or bile salts for 3 h. None showed haemolytic activity. All were resistant to most antimicrobials tested, but were sensitive to imipenem. Most strains inhibited the growth of Salmonella Typhimurium while five inhibited growth of V. cholerae O139. Seven strains showed adherence to Caco-2 cells ranging from 20-104 per cent of adherence of an adherent strain of Escherichia coli, but all inhibited V. cholerae adherence to Caco-2 cells by 20-100 per cent. They inhibited interleukin-8 secretion from HT-29 cells, in response to V. cholerae, by 50-80 per cent. Two strains induced IL-10 and IL-12 messenger ribonucleic acid (mRNA) expression in THP-1 cells.
INTERPRETATION & CONCLUSIONS: LAB in curd had properties consistent with probiotic potential, but these were not consistent across species. LAB abundance in curd increased rapidly at 12 h of fermentation at room temperature and declined thereafter.
人类肠道微生物群在营养过程中发挥着重要作用。益生菌的概念导致了含有益生菌微生物（如凝乳和酸奶）的食品制剂的广泛消费。在印度南部的大多数家庭中，每天都会食用家中自制的凝乳。在本研究中，对自制凝乳中的乳酸菌（LAB）进行了具有益生菌潜力的评估。
对从自制凝乳中分离出的15株乳酸菌（12株乳酸杆菌、1株嗜热链球菌、2株明串珠菌）和1株酵母菌进行了耐酸性、胃蛋白酶、胰酶和胆盐能力；抗菌药物耐药性；固有抗菌活性；对Caco-2上皮细胞的黏附能力；阻断病原体对Caco-2细胞黏附的能力；抑制霍乱弧菌刺激HT-29上皮细胞分泌白细胞介素（IL）-8的能力；以及诱导THP-1单核细胞中抗炎细胞因子表达的能力的评估。
发酵凝乳中乳酸杆菌的丰度在12小时时急剧达到峰值。其中9株菌株在pH 3.0的酸性环境中存活至少1小时，所有菌株在胰酶或胆盐存在的情况下存活3小时。均未表现出溶血活性。所有菌株对大多数测试抗菌药物耐药，但对亚胺培南敏感。大多数菌株抑制鼠伤寒沙门氏菌的生长，而5株抑制霍乱弧菌O139的生长。7株菌株对Caco-2细胞的黏附率为黏附性大肠杆菌菌株黏附率的20%-104%，但均能将霍乱弧菌对Caco-2细胞的黏附抑制20%-100%。它们能将霍乱弧菌刺激HT-29细胞分泌的白细胞介素-8抑制50%-80%。两株菌株在THP-1细胞中诱导白细胞介素-10和白细胞介素-12信使核糖核酸（mRNA）表达。
凝乳中的乳酸菌具有与益生菌潜力相符的特性，但这些特性在不同物种间并不一致。室温下发酵12小时时，凝乳中乳酸菌的丰度迅速增加，此后下降。
