Why? Your Gut Microbiome!

"We had this concern that it would be difficult to recruit people[for an endocrinological study] because there's a certain yucki factor with having to take a poop pill."
"But we had an overwhelming number of volunteers [respond to an invitation to take part in the study]."
"It would be great if there was a treatment that could come out of this research [Canadian study in fecal transplants]."
"But I don't think we're going to find some magic portion that will be able to cure obesity in the absence of any other intervention."
Dr. Elaine Yu, endocrinologist, Massachusetts General Hospital, Boston

Credit: S. Bradbrook / Springer Nature Limited

Dr.Yu evidently -- as anyone might -- underestimated the public's interest in why it is that some people tend to a lean conformation while others become obese. Popularly, people nod wisely and speak of the functioning high metabolism some are gifted with, enabling them to eat what they wish without gaining excess weight. So when she advertised for volunteers and was inundated with responses several years ago by members of the public eager to take part in her experimental study she was surprised.

There have been recently revealed clues that microbiota, the trillions of microbes that inhabit the gut, play a role in weight gain and metabolic disease. Scientists now explore whether changes in metabolism and body weight can be manipulated with the aid of fecal microbiota transplants (F.M.T.), where gut bacteria from lean donors are transferred to the guts of obese patients. And while the process shows some promise, research thus far has concluded with mixed results.

There are those experts who feel that irrespective of what biological interventions can be contrived  such as fecal transplants, the much simpler to advise, but difficult to convince patients of the need to alter lifestyle by changing diet and activity level to purposefully see positive weight and health impacts will always be superior in functionality and outcome. Those two issues; diet and exercise, can work wonders to prevent obesity and Type 2 (formerly adult-onset) diabetes.

On the other hand, some scientists subscribe to the belief that it is possible to discover bacteria whose purpose is to protect against metabolic disease. That the microbiomes of obese and lean people differ has been known by scientists for some time. Less microbial diversity is recognized as leading to obesity, insulin resistance and fatty liver disease. When obese mice have their microbiota transplanted into lean mice the formerly lean mice gain weight.

A bacterial infection, Clostridium difficile, was proven to be effectively treated with fecal transplants to deal with the bacterial infection occurring when antibiotics destroy healthy gut bacteria. There is one telling case of a lean woman receiving an F.M.T. from her overweight daughter to treat C. diff, and she swiftly gained 15 kilograms. Although intuition linked the daughter's F.M.T. to the mother's weight gain, her doctors would not commit to crediting it with that effect.

In 2012, researchers in the Netherlands demonstrated that transferring a lean donor's microbiota to obese men with metabolic syndrome succeeded in increases in insulin sensitivity and microbial diversity following six weeks of treatment. In Dr. Yu's study, the 24 obese individuals with insulin resistance whom she recruited were divided into two teams, half of whom took capsules of stool from lean donors weekly, while the other half received a placebo.

Subjects receiving the F.M.T. after 12 weeks had microbiota resembling that of the donors, but no improvement was seen in metabolic health. In the Canadian study, the effects of fecal transplants on people with fatty liver disease was examined with the authors concluding that the treatment led to changes in the guts of the recipients, producing the effect of a less "leaky" gut membrane.

The immune system alters gut bacteria in dietary fats absorption animaxx3d/Depositphotos

There is a hypothesis to explain how an abnormal microbiome could contribute to metabolic disease and weight gain through damaging the gut barrier keeping toxins and pathogens from crossing into the bloodstream. Once those toxins and pathogens enter the bloodstream, they are able to set off inflammation contributing to insulin resistance, cardiovascular disease and autoimmune conditions, according to the lead author of the study, Dr.Michael Silverman.

It's Not the Bacterial Count, Stupid!

"These kinds of stories are irritating. It's always something: kids' toys, doorknobs, touch screens. These are all the same objects touched by people."
"Of course there will be human-associated bacteria on them. Washing  your hands more or less does the trick."
David Coil, microbiologist, University of California at Davis

"Our self-order screens are cleaned frequently throughout the day with a sanitizer solution."
"All of our restaurants also provide facilities for customers to wash their hands before eating."
McDonald's statement

"We were all surprised how much gut and fecal bacteria there was on the touchscreen machines. These cause the kind of infections that people pick up in hospitals."
"Touchscreen technology is being used more and more in our daily lives but these results show people should not eat food straight after touching them, they are unhygienic and can spread disease." "Someone can be very careful about their own hygiene throughout the day but it could all be undone by using a touchscreen machine once."
Dr. Paul Matewele, senior lecturer in microbiology, London Metropolitan University

Queuing to order  your food may be the safest option in avoiding harmful bacteria acquired from touchscreens. Photo: Bloomberg LP

Paul Matewele, a senior lecturer in microbiology at London Metropolitan University, undertook some interesting, but perhaps predictable research where  his team of researchers visited eleven McDonald's restaurant outlets in London and Birmingham to take swab samples from the chain's touch screens. Three weeks of tests followed, leading Dr. Matewele to discover ten types of bacteria, three of which are harmless, to be living on those touch screens.

Those bacteria present on the swabs taken from the touch screens that did cause some concern are coliforms associated with the human gut, along with enterococcus faecalis (from fecal matter) and enterobacter, which can be found in intestines; staphylococcus normally found in nasal passages; klebsiella found in the mouth or threat and finally; micrococcus which usually make their home on human skin.

These are bacteria capable of causing urinary tract infection, pneumonia, and septicemia in people who come in contact with them, who happen to have compromised immune systems. These bacteria are also known for their ability to cause infections that people typically can acquire when they are in a hospital setting. Dr. Matewele, specializing in microbiology and immunology clarified that many bacteria are not harmful; some indeed are useful residents of our immune system.

His intention in conducting the tests was not to point a finger of blame on fast food giant McDonald's, but rather to merely to raise awareness in the public, and most particularly among that demographic who regularly consume food at restaurants or other public places. And, as Dr. Coil points out -- unless it can be determined who touched the screens at McDonald's it remains impossible to determine how threatening those surfaces can be; whether in fact they're at all dangerous.


The bacteria that teem in uncountable numbers on McDonald's touch screens are those that live in the gut, intestines, nose, skin, mouth throat and stools while some live in soil and water. All humans host these types of bacteria, some harmless, others potential threats under certain circumstances. With the trillions of bacterial cells that humans carry both within and without our bodies, leaving some and acquiring others wherever we come in communication with objects other people touch, most are unlikely to do harm to a healthy body.

We touch objects that other people come in contact with continually on a daily basis, from doorknobs to elevator buttons, shopping carts, handrails, bus and subway stations, just about anywhere where people tend to frequent. And where most frequently encountered than in popular fast-food outlets? Apart from which there have never been public health reports linking infections caused by bacteria-infested touch screens at McDonald's or any other fast-food restaurants.

Of course, it's always a good idea to wash one's hands. It is why hospitals, where sick people tend to congregate and where bacterium are shed and picked up and infections often result with extended exposure, have those pumps with sanitizing liquid at the disposal of passersby. So use them wherever they are, including fastened to the walls at supermarkets.

If there is any reason to be leery of acquiring something deleterious to one's health at McDonald's or any other fast-food emporiums, it is unhealthy food choices, which when overindulged results in unhealthy consequences, leading eventually to poor nutritional uptake, overweight and obese bodies and the propensity for contracting chronic diseases like diabetes in turn leading to cardiovascular problems....

Photo: Susannah Ireland for Metro.co.uk