科学家们的一项新研究称，人大肠中的细胞可能减缓"好"脂肪组织的活性，这里的"好"脂肪组织是一类能快速燃烧热量、有助于预防肥胖的特殊脂肪。这个发现发表在ACS的Journal of Proteome Research上，它照亮了预防肥胖与促进体重减轻的道路，包括成功研究出微生物治疗方法与药物的可能。
Sandrine P. Claus，Jeremy K. Nicholson和同事们这样解释，数百万细菌存在于健康人的大肠中，在那里他们帮助消化食物和制造特定的维生素。但最近，科学家们已认识到这些细菌能做得更多——他们以影响能量使用与贮藏的方式与其所在之处相互作用，并精细地调节免疫系统。Claus 和 Nicholson决定观察肠细菌如何影响褐色脂肪的活性。"好"脂肪在被贮存为脂肪之前快速地燃烧热量，褐色脂肪小量地存在于颈和其他地方--不象腰部与臀部周围松弛的白色脂肪。研究人员强调还没有人观察过这些细菌是否对褐色脂肪有作用。
在"无菌"（GF）小鼠（没有大肠内细菌）与正常小鼠的对照实验中，科学家们揭示了细菌影响褐色脂肪活性的证据。GF小鼠中的褐色脂肪似乎更有活性，燃烧热量快于正常小鼠中的。正常雄性小鼠比雌性更重、更肥，但是这些区别在GF小鼠中就消失了。研究也揭示了雄雌性小鼠与它们的肠道菌间相互作用的主要区别，这可能有助于解释为什么肥胖流行在妇女中更严重、发展更迅速。这些和其他的发现可指出一条通向激发人体内褐色脂肪活性以预防或治疗肥胖症的道路。（生物谷bioon.com）
doi:10.1021/pr200938v
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Gut Microbiota Modulate the Metabolism of Brown Adipose Tissue in Mice
Renaud Mestdagh, Marc-Emmanuel Dumas, Serge Rezzi, Sunil Kochhar, Elaine Holmes, Sandrine P. Claus, Jeremy K. Nicholson
Abstract A two by two experimental study has been designed to determine the effect of gut microbiota on energy metabolism in mouse models. The metabolic phenotype of germ-free (GF, n = 20) and conventional (n = 20) mice was characterized using a NMR spectroscopy-based metabolic profiling approach, with a focus on sexual dimorphism (20 males, 20 females) and energy metabolism in urine, plasma, liver, and brown adipose tissue (BAT). Physiological data of age-matched GF and conventional mice showed that male animals had a higher weight than females in both groups. In addition, conventional males had a significantly higher total body fat content (TBFC) compared to conventional females, whereas this sexual dimorphism disappeared in GF animals (i.e., male GF mice had a TBFC similar to those of conventional and GF females). Profiling of BAT hydrophilic extracts revealed that sexual dimorphism in normal mice was absent in GF animals, which also displayed lower BAT lactate levels and higher levels of (D)-3-hydroxybutyrate in liver, plasma, and BAT, together with lower circulating levels of VLDL. These data indicate that the gut microbiota modulate the lipid metabolism in BAT, as the absence of gut microbiota stimulated both hepatic and BAT lipolysis while inhibiting lipogenesis. We also demonstrated that 1H NMR metabolic profiles of BAT were excellent predictors of BW and TBFC, indicating the potential of BAT to fight against obesity
