By Benjamin V. Treadwell, Ph.D.

We wash our hands, scrub the floors, sanitize our surroundings, and cook our foods, sometimes obsessive-compulsively, to destroy those dirty, nasty microorganisms we know as bacteria or bugs. But are all bugs bad for our health? Or have some evolved in a symbiotic way?

100 Trillion Microbes
They are on our skin and in our mouths. In fact, the microbes outnumber the cells comprising the tissues and organs of our body, and contain a hundred times more genetic information than what’s in our genetic profile. And the bulk of them thrive within our digestive system.

The gut is teaming with microbes that, under normal circumstances, do not produce disease. In fact, the genes contained within the numerous different species of intestinal bugs code for enzymes that are capable of digesting a variety of food materials, such as normally indigestible plant polysaccharides.

Digestive Bug-organ
These digestive system microbes have evolved with man’s predecessors, functioning in a symbiotic way to help protect them from starvation. This was a fantastic advantage for early man for at least two important reasons. First, man was not limited to those foods his genetic makeup was competent at converting to energy and, second, man did not have to carry within his genome the extra genetic garbage to produce the enzymes the bugs furnish.

This large community of genetically diverse bugs functioned as an extra organ, as it continues to function today. A free gift to man in a way, our "bug-organ" does, however, need to be supplied with the proper nutrients to maintain a healthy balance or ratio between its microbe species.

Firmicutes and Bacteroidetes
The gut microbes, for the most part, belong to two of the 70 known divisions of bacteria: the Firmicutes and the Bacteroidetes, each of which contains thousands of different species. The ratio between these two divisions of organisms has been recently demonstrated to vary with an individual’s weight.

The lean individual’s gut bacteria has a ratio of about 40% Bacteroidetes to 60% Firmicutes. With weight gain, edging toward the obese condition, Bacteroidetes decrease to 20% while Firmicutes increase to 80%. With weight loss, the ratio reverts back to the lean condition. So, a laboratory test of the Bacteroidetes-Firmicutes ratio in intestinal bacteria can determine whether a person is overweight. (Of course, it would be far simpler to step onto a bathroom scale).

Diet and the Bacterial Ratio
Why does the bacterial ratio change with an individual’s weight and what does that mean in terms of our health? The investigation is just beginning. (See this month’s Research Update.) There is no question that eating to excess is a major contributor to the obese condition and its associated health risks. However, it now appears that obesity itself also contributes to an increase in fat storage via a pronounced change in the ratio of bacteria.

Early man was never obese, but did eat excessively under those rare conditions when food was plentiful. He needed to ingest and store as many nutrients as possible during those intermittent times of food excess, and a change in the bacterial ratio to favor increased fat/energy storage was an added advantage.

Historic periods of food scarcity contrast sharply with modern Western diets of copious amounts of calorie-rich processed foods with little non-digestible fiber. Consequently the change in bacterial ratio with weight gain, and the associated storage of food-derived energy as fat, has become a health hazard rather than an advantage.

More Bug-organ Basics
It is not yet known why a change in this bacterial ratio predisposes one to increased fat storage. One reasonable speculation is that the gut microbial organ automatically alters the residing bacterial types in response to increased food intake so as to increase maximum absorption, which was vital for ancient man’s survival. However, in today’s industrialized world there is constant exposure to excess junk food (Western-style food), confusing the microbial gut organ into believing it must work to convert all of it to digestible components to be stored as fat.

Although the bacterial residents of our intestines seem to play a role in excessive fat storage, they also provide numerous health benefits. For example, many of the vitamins we need to survive are produced from our diet by intestinal bacteria, albeit at a low level.

On the other hand, a change in the composition of the species of bacteria residing in our intestines, by ingestion of a pathogenic bacterial species, diet or the use of antibiotics, can result in disease. Furthermore, the experts involved in this research are likely to discover additional critical relationships between the gut microbiota and our health and longevity.

In short, these microorganisms, their health and their healthy ratio are vital to our health. Maintaining a nutritious diet and avoiding excess caloric intake - especially high-sugar and processed foods as well as refined grains and saturated fats - will help promote a healthy intestinal microbial community and its many benefits.

Fredrik Bäckhed, Jill K. Manchester, Clay F. Semenkovich and Jeffrey I. Gordon recently published some interesting findings in their article in the January 16, 2007 issue of Proceedings of the National Academy of Sciences.

The four researchers, from the Center for Genome Sciences and Department of Medicine of the Washington University School of Medicine (St. Louis, MO), investigated the role that the trillions of intestinal microorganisms play in the metabolism of food and the development of obesity. Specifically, they compared the metabolisms of mice raised in a germ-free environment to those raised in a normal environment, focusing on how and why intestinal microbes promote obesity.

In their studies, the germ-free animals maintained a lean healthy weight even when fed a Western-style diet high in fat and sugar. The mice raised in a normal germ-containing environment, on the other hand, became obese even while consuming the same number of calories as their germ-free counterparts.

The authors attribute these different reactions to two distinct pathways involving two metabolic regulators affected by the intestinal microbial community.

To read the abstract, click here.
"Mechanisms underlying the resistance to diet-induced obesity in germ-free mice."
PNAS | January 16, 2007 | vol. 104 | no. 3 | 979-984

This Research Update column highlights articles related to recent scientific inquiry into the process of human aging. It is not intended to promote any specific ingredient, regimen, or use and should not be construed as evidence of the safety, effectiveness, or intended uses of the Juvenon product. The Juvenon label should be consulted for intended uses and appropriate directions for use of the product.

QUESTION: I am writing to learn more about side effects that may be experienced with Juvenon. Personally, I have been experiencing a very alert brain (great!), but also a sense that my heart is racing (it isn't), or that my adrenaline has shot up. It's kind of like I'm on overdrive, and it feels a little scary. Have you spoken with others who have had these effects?
RA

ANSWER: The side effects you describe are rare, but we have had such reports of a hyped-up feeling after starting on Juvenon™ Cellular Health Supplements. I suggest you try taking only one tablet per day and take it early in the day. Some people have described a hyperactive state when taking too much Juvenon, and for some people this could be two tablets per day.

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Benjamin V. Treadwell, Ph.D., is a former Harvard Medical School associate professor and member of Juvenon's Scientific Advisory Board.