&quot;If you want to stay lean, you&#x27;ll want bacteria that are not very efficient&quot;<p>I hope this article isn&#x27;t suggesting that it is preferable to have less efficient digestive systems so that we can all eat more.  Given the environmental impact of food production these efficient digestion microbes are something we should encourage. Maybe they are harmful because of insulin spikes ? But the article doesn&#x27;t mention this.