科学家们发现了可以增强运动动力的肠道微生物类型

研究人员在老鼠身上发现了一种肠道到大脑的通路，可以提高运动表现。

根据发表在 自然由佩雷尔曼医学院的研究人员领导 宾夕法尼亚大学某些类型的肠道细菌可以激活肠道神经，从而增加锻炼的动力。 对小鼠的研究确定了一条从肠道到大脑的通路，解释了这些细菌如何提高运动表现。

研究发现，一组实验室小鼠的跑步表现差异主要是由于表现较好的小鼠肠道中存在某些细菌种类所致。 研究人员确定，这种效应与这些细菌产生的称为代谢物的小分子有关。 这些代谢物激活肠道中的感觉神经，进而增加大脑中控制运动动机的区域的活动。

“如果我们能够证实人类存在类似的途径，它可以提供一种有效的方法来提高人们的运动水平，从而改善整体健康状况，”该研究的资深作者、微生物学助理教授 Christoph Theiss 博士说。 在宾夕法尼亚医学。

Theis 和他的同事开展了这项研究，以广泛研究决定运动表现的因素。 他们对基因组、肠道细菌类型、血液代谢物和遗传多样性小鼠的其他数据进行了测序。 然后，他们测量了这些动物每天自愿转身的次数，以及它们的耐力。

研究人员使用机器学习分析了这些数据，寻找能够最好地解释个体之间跑步表现显着差异的小鼠特征。 他们惊讶地发现，基因似乎只占这些性能差异的一小部分——而肠道细菌种群的差异似乎呈指数级增长。 事实上，他们观察到，给老鼠一种广谱抗生素来清除它们的肠道细菌会使老鼠的跑步成绩降低近一半。

最终，在涉及宾夕法尼亚州和其他地方十几个独立实验室的多年科学研究工作中，研究人员发现两种细菌与更好的表现密切相关， 直肠真杆菌 和 粪球菌产生称为脂质体的代谢物[{” attribute=””>acid amides (FAAs). The latter stimulates receptors called CB1 endocannabinoid receptors on gut-embedded sensory nerves, which connect to the brain via the spine. The stimulation of these CB1 receptor-studded nerves causes an increase in levels of the neurotransmitter dopamine during exercise, in a brain region called the ventral striatum.

The striatum is a critical node in the brain’s reward and motivation network. The researchers concluded that the extra dopamine in this region during exercise boosts performance by reinforcing the desire to exercise.

“This gut-to-brain motivation pathway might have evolved to connect nutrient availability and the state of the gut bacterial population to the readiness to engage in prolonged physical activity,” said study co-author, J. Nicholas Betley, Ph.D., an associate professor of Biology at the University of Pennsylvania’s School of Arts and Sciences. “This line of research could develop into a whole new branch of exercise physiology.”

The findings open up many new avenues of scientific investigation. For example, there was evidence from the experiments that the better-performing mice experienced a more intense “runner’s high”—measured in this case by a reduction in pain sensitivity—hinting that this well-known phenomenon is also at least partly controlled by gut bacteria. The team now plans further studies to confirm the existence of this gut-to-brain pathway in humans.

Apart from possibly offering cheap, safe, diet-based ways of getting ordinary people running and optimizing elite athletes’ performance, he added, the exploration of this pathway might also yield easier methods for modifying motivation and mood in settings such as addiction and depression.

Reference: “A microbiome-dependent gut–brain pathway regulates motivation for exercise” by Lenka Dohnalová, Patrick Lundgren, Jamie R. E. Carty, Nitsan Goldstein, Sebastian L. Wenski, Pakjira Nanudorn, Sirinthra Thiengmag, Kuei-Pin Huang, Lev Litichevskiy, Hélène C. Descamps, Karthikeyani Chellappa, Ana Glassman, Susanne Kessler, Jihee Kim, Timothy O. Cox, Oxana Dmitrieva-Posocco, Andrea C. Wong, Erik L. Allman, Soumita Ghosh, Nitika Sharma, Kasturi Sengupta, Belinda Cornes, Nitai Dean, Gary A. Churchill, Tejvir S. Khurana, Mark A. Sellmyer, Garret A. FitzGerald, Andrew D. Patterson, Joseph A. Baur, Amber L. Alhadeff, Eric J. N. Helfrich, Maayan Levy, J. Nicholas Betley and Christoph A. Thaiss, 14 December 2022, Nature.
DOI: 10.1038/s41586-022-05525-z

The study was funded by the National Institutes of Health, the Pew Charitable Trust, the Edward Mallinckrodt, Jr. Foundation, the Agilent Early Career Professor Award, the Global Probiotics Council, the IDSA Foundation, the Thyssen Foundation, the Human Frontier Science Program, and Penn Medicine, including the Dean’s Innovation Fund.