Vernekar Manvi, Singhal Rekha, Joshi Kalpana, Amarapurkar Deepak
1 Department of Food Engineering and Technology, Institute of Chemical Technology , Mumbai, India .
2 Department of Biotechnology, Sinhgad College of Engineering, Savitribai Phule Pune University , Pune, India .
Metab Syndr Relat Disord. 2018 Sep;16(7):329-335. doi: 10.1089/met.2018.0008. Epub 2018 Jun 6.
Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are becoming a major cause of chronic liver diseases globally. Polyunsaturated fatty acids (PUFA) have been postulated as a potential treatment for NAFLD. They can be obtained from diet and are also endogenously synthesized by enzymes delta-6-desaturase (D6D), delta-5-desaturase, and elongases. The current study is aimed at investigating the differences in the intake and levels of plasma PUFA between NAFLD patients and controls in Asian Indians. This correlation further propelled a pilot study to check for the differences in the gut microbiome of NASH subjects versus controls.
One hundred forty-seven subjects were recruited and were grouped into healthy controls and cases. Subjects filled a food frequency questionnaire to assess PUFA intake. Plasma samples were subjected to gas chromatography analysis. For characterizing the gut microbiome, fecal samples of 20 NASH and healthy controls were analyzed by 16s rRNA gene sequencing. Alpha and beta diversity metrics and taxonomic analysis were carried out.
Plasma levels of eicosapentaenoic acid, γ-linoleic acid and D6D enzyme activity were significantly lower in cases. Dietary intake of total n-6 and n-3 PUFA did not differ between the two groups. Relative abundance of Streptococcus and Clostridium ramosum was significantly higher in NASH patients compared with healthy controls.
This study demonstrates, for the first time, decreased D6D enzyme activity and plasma PUFA levels in NAFLD patients. Furthermore, it demonstrates gut dysbiosis in histologically proven NASH patients vis-à-vis healthy controls.
非酒精性脂肪性肝病（NAFLD）和非酒精性脂肪性肝炎（NASH）正成为全球慢性肝病的主要病因。多不饱和脂肪酸（PUFA）被认为是治疗NAFLD的一种潜在方法。它们可以从饮食中获取，也可由δ-6-去饱和酶（D6D）、δ-5-去饱和酶和延长酶内源性合成。本研究旨在调查亚洲印度人NAFLD患者与对照组之间血浆PUFA摄入量和水平的差异。这种相关性进一步推动了一项初步研究，以检查NASH受试者与对照组肠道微生物群的差异。
招募了147名受试者，并将其分为健康对照组和病例组。受试者填写食物频率问卷以评估PUFA摄入量。对血浆样本进行气相色谱分析。为了表征肠道微生物群，通过16s rRNA基因测序分析了20名NASH患者和健康对照的粪便样本。进行了α和β多样性指标及分类学分析。
病例组中二十碳五烯酸、γ-亚麻酸的血浆水平和D6D酶活性显著降低。两组之间总n-6和n-3 PUFA的饮食摄入量没有差异。与健康对照组相比，NASH患者中链球菌和多枝梭菌的相对丰度显著更高。
本研究首次证明NAFLD患者的D6D酶活性和血浆PUFA水平降低。此外，与健康对照组相比，本研究证明了经组织学证实的NASH患者存在肠道菌群失调。
