Nakkarach Atchareeya, Foo Hooi Ling, Song Adelene Ai-Lian, Nitisinprasert Sunee, Withayagiat Ulaiwan
Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University, 50 Ngam Wong Wan Road, Lat Yao, Chatuchak, Bangkok, 10900 Thailand.
Department of Bioprocess, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor Malaysia.
3 Biotech. 2020 Jul;10(7):296. doi: 10.1007/s13205-020-02289-z. Epub 2020 Jun 9.
Ingested dietary fibres are hydrolysed by colon microbiota to produce energy-providing short-chain fatty acids (SCFA) that stimulate anti-inflammatory effects. SCFA-producing bacteria were screened from bacteria isolated from human faeces using bromothymol blue as an acid indicator and gas chromatography for SCFA profiling. The beneficial functions (antagonistic activity, haemolytic activities, antibiotic susceptibility, mucus adherent percentage and toxin gene detection) were evaluated for the top five SCFA-producing bacteria isolated from three healthy volunteers that identified as strains. They produced acetic, propionic, isobutyric, butyric, isovaleric, valeric and caproic acids at average concentrations of 15.9, 1.8, 1.1, 1.9, 1.8, 2.7 and 3.4 mM, respectively. The SCFA production by strains was rapidly increased during the first 8 h of incubation and gradually decreased after 16 h of incubation. All strains showed acid and bile tolerance, resulting in a survival rate greater than 70% with no haemolytic activity, mucus adherence greater than 40% and susceptibility to conventional antibiotics. Hence, the selected strains exhibited promising probiotic properties with neither enterotoxin nor LPS producibility was detected. The present results confirm the existence of friendly and harmless strains in human microbiota as potential probiotics.
摄入的膳食纤维被结肠微生物群水解，产生提供能量的短链脂肪酸（SCFA），从而发挥抗炎作用。以溴百里酚蓝作为酸指示剂，利用气相色谱法分析SCFA，从人类粪便分离出的细菌中筛选出产生SCFA的细菌。对从三名健康志愿者中分离出的、鉴定为菌株的前五名产生SCFA的细菌进行了有益功能（拮抗活性、溶血活性、抗生素敏感性、黏液黏附百分比和毒素基因检测）评估。它们分别产生乙酸、丙酸、异丁酸、丁酸、异戊酸、戊酸和己酸，平均浓度分别为15.9、1.8、1.1、1.9、1.8、2.7和3.4毫摩尔。菌株产生SCFA的量在培养的前8小时迅速增加，培养16小时后逐渐减少。所有菌株均表现出耐酸和耐胆汁的特性，存活率大于70%，无溶血活性，黏液黏附率大于40%，且对传统抗生素敏感。因此，所选菌株表现出有前景的益生菌特性，未检测到产生肠毒素或脂多糖的情况。目前的结果证实了人类微生物群中存在友好且无害的菌株作为潜在的益生菌。
