Our food is filled with antibiotics. Here's what you should know about it

Antibiotics and obesity

Marty Blazer, a New York-based microbiologist, was one of the first to recognize the potential and long-term dangers of both antibiotics and our flawed attempts to fight germs without regard to the consequences. The first time I heard him speak at a geneticist conference on Long Island in 2009, he convinced me of the reality of such threats. To date, he has published an excellent book Blaser, M., Missing Microbes (Henry Holt, 2014). on this issue.

Like many of us, Marty Blazer studied the results of a government study on how the prevalence of obesity changed in 21 years in different states of America. The results were visualized as color maps showing changes over time.

Antibiotics in food: prevalence of obesity in different states of America

Honestly, it looks like a horror movie! Colors change from blue (less than 10% of obesity cases) in 1989 to dark blue, brown, then red (over 25%), very reminiscent of the spread of the plague. In 1999, obesity rates in no state fell below 14%. By 2010, that bar had risen to 20% even in the healthiest state, Colorado. The highest rates were observed in the southern states, the lowest in the western ones. Today, over a third (34%) of the US adult population is obese.

Explaining such dramatic changes is not easy. However, you can try. In 2010, data on the frequency of antibiotic use in the same states were published, and again the large differences across the country could not be attributed to disease or demographic factors. Surprisingly, the colors on the obesity and antibiotic use maps overlapped.

The southern states, which were most often treated with antibiotics, were also the leaders in obesity. In California and Oregon, antibiotics were used the least (on average 30% less than in other states), and it was here that residents were less likely to suffer from obesity.

We now well know that observational studies on a national scale like the above are far from perfect. For example, you could map the United States where obesity is correlated with Facebook use or body piercing. This means that the conclusions of the two studies considered are not so reliable. There was an obvious need for repeated experiments to confirm the hypothesis of a correlation between obesity and antibiotic use.

The first such opportunity came with data from the ALSPAC (Avon Longitudinal Study of Parents and Children) project, which I worked with frequently. Under this project, Trasande, L., Int J Obes (Jan 2013); 37 (1): 16-23. Infant antibiotic exposures and earlylife body mass. Scientists have been observing 12,000 Bristol children since birth, carefully collecting measurement data and medical records. It turned out that antibiotic use in the first six months of life led to a significant (22%) fat gain in children and an increased overall risk of obesity in the next three years. A later study found a weaker effect of antibiotics and no effect of other drugs. Danish study Ajslev, T. A., Int J Obes 2011; 35: 522-9. Childhood overweight after establishment of the gut microbiota: the role of delivery mode, prepregnancy weight and early administration of antibiotics. an association was found between antibiotic use in the first six months of life and subsequent weight gain by the age of seven.

A recent larger study by Bailey, L. C., JAMA Pediatr (29 Sep 2014); doi: 10.1001 / jamapediatrics. Association of antibiotics in infancy with early childhood obesity. in the United States, with the participation of 64 thousand children, gave scientists the opportunity to compare the types of antibiotics used and the exact timetable for taking them. About 70% of Pennsylvania children under the age of two received an average of two courses of antibiotics.

Scientists have found that taking broad-spectrum antibiotics before this age increases the risk of obesity in babies by an average of 11%, and the earlier the medication is started, the higher the risk.

In contrast, narrow-spectrum antibiotics did not have a clear effect, as is the case with common infections. These "epidemiological" results, while supporting certain conclusions, are still inconclusive and may be explained by other biased factors: for example, children taking antibiotics are different from others or more susceptible to drugs.

Marty Blazer and his team took it one step further by testing their theory in mice. To mimic the effects of antibiotics on babies in the first three years of life, the scientists divided the offspring of laboratory mice into two groups. The first was given three shots of antibiotics in five days at doses equivalent to those given to babies for ear or throat infections. After antibiotics, both groups received a generous high-fat diet for five months followed by Blaser, M., Nat Rev Microbiol (Mar 2013); 11 (3): 213-17. The microbiome explored: recent insights and future challenges. tests and comparison with the group not receiving antibiotics. The results were clear and striking: the mice that received the antibiotics showed significant gain and increased body fat, most of all in the mice on a high-fat diet.

With the exception of the lucky ones, most people born in the past 60 years have not been able to avoid taking antibiotics in childhood or a fatty diet at some point in their lives, so we suffer the same consequences as laboratory mice.

I asked our 10,000 English twins if there were any among them who had never taken antibiotics. Alas, not a single such individual was found. Even if as a child you (like me) managed to escape antibiotic therapy, you may have been born as a result of a cesarean section. After adjustments for other factors, meta-analysis Darmasseelane, K., PLoS One (2014); 9 (2): e87896.doi: 10.1371. Mode of delivery and offspring body mass index, overweight and obesity in adult life: a systematic review and metaanalysis. showed that if you were born with a caesarean section and did not go through the magic swab treatment, your risk of obesity is probably 20% higher, which, in my opinion, should be attributed to germs.

Animal addicts

Most of the antibiotics that are manufactured and marketed are not made for humans. In Europe, about 70% of antibiotics are intended for agriculture, and again there are major differences in their use in neighboring countries. In the United States, approximately 80% of all antibiotics are currently consumed by the farming community. However, they are used in huge quantities - about 13 million kg in 2011 compared with just 50 kg in the 1950s.

These poor animals must be suffering from throat problems, you think? No, actually antibiotics are used for other reasons.

In the post-war years and up to the 1960s, scientists did not try to stimulate animals to grow faster Visek, W. J., J Animal Sciences (1978); 46; 1447-69. The mode of growth promotion by antibiotics. … Finally, after a long period of trial and error, they discovered that the constant addition of low doses of antibiotics to the feed causes rapid growth in almost all animals, which means that they can be sent to the market faster and with less cost - this provides the most efficient feed efficiency, or conversion stern. Moreover, the sooner you start feeding animals "special" food, the better the results will be.

The production of antibiotics became cheaper, and their use brought more and more benefits to the industry. And if it worked so well on cattle and poultry, why not transfer the experience to humans? American farms no longer resemble farms in the usual sense of the word. Today these are huge, industrial-scale feedlots, which are called CAFO (large fattening enterprises) and which can contain up to 500 thousand chickens or pigs and up to 50 thousand head of cattle.

Cattle are raised at a super-fast pace: from calving to slaughter, it takes about 14 months, and by this time the average weight of the animal reaches Pollan, M., The Omnivore's Dilemma (Bloomsbury, 2007). astonishing size - 545 kg. Calves are quickly converted from natural hay and grass to corn mixed with low doses of antibiotics.

Corn is cheap thanks to subsidies, it grows in surplus because it is grown in huge fields filled with pesticides, the total area of which is comparable to the entire UK. Due to the new artificial diet that makes animals sick, overcrowding, lack of fresh air and inbreeding, animals are prone to infectious epidemics, so, paradoxically, antibiotics are beneficial to them.

Few antibiotics are banned from American agriculture. The USDA was reluctant to get involved in this lucrative business. In 1998, realizing the consequences of antibiotics that are introduced into the human food chain and cause drug addiction, the more environmentally friendly European Union imposed a ban on feeding animals certain drugs that are valuable to human health. Then, in 2006, all drugs were banned, including antibiotics that were used to stimulate growth.

This would mean that most of the meat in Europe is antibiotic-free. Unfortunately, this is not at all the case: illegal addition of them to feed occurs at every turn, as the recent scandals in the Netherlands have shown. EU farmers are still officially allowed to administer antibiotics when problems arise, and they use it regularly, often overdosing. The EU is trying to limit the list of approved antibiotics, but in reality the situation is poorly controlled.

It is cheaper for a farmer with a sick animal in the herd to treat all five hundred heads than to isolate one sick cow and see what happens.

Such huge amounts of antibiotics in the food chain and in the environment are causing an increase in microbial resistance, which means that stronger antibiotics are required - first for animals, and then for us humans.

Pastoralists outside Europe do not adhere to even the most liberal rules. Moreover, the European Union imports large quantities of food, so it is not always known where the semi-finished meat product comes from, or even whether it is really made from the meat indicated on the package (remember the horse meat scandals in lasagna).

More than a third of seafood is intensively grown industrially, be it salmon from Norway or Chile, or shrimp from Thailand or Vietnam. Antibiotics are now used in huge quantities in fish farms, and most of the large suppliers are outside the control of the American or European authorities. The worse the conditions for hatching the fish, the more tons of antibiotics are required. Burridge, L., Aquaculture (2010); Elsevier BV 306 (1-4): 7-23 Chemical use in salmon aquaculture: a review of current practices and possible environmental effects., over 75% of the antibiotics that are fed to fish on farms go through the cages into the water, where they are eaten by fish swimming nearby, such as cod, and with it the drugs enter the food chain.

Can antibiotics be saved?

So, if you love meat and fish, you are most likely getting antibiotics with your steaks, pork chops, or salmon. It's illegal, but in many countries, small amounts of antibiotics are found in milk. Even if you are a staunch vegan, you are still not safe. Especially in the United States (and other countries too), animal dung containing antibiotics is used as fertilizer for plants and vegetables that may end up on your plate.

And our water is polluted by millions of tons of antibiotics, which go down to sinks and toilets, animal waste, and contains many colonies of bacteria resistant to antibiotics. Water companies are silent about the fact that they do not have the ability to track or filter antibiotics and resistant bacteria. Large amounts of antibiotics found by Karthikeyan, K. G., Sci Total Environ (15 May 2006); 361 (1-3). Occurrence of antibiotics in wastewater treatment facilities in Wisconsin, USA. in wastewater treatment plants in Europe and the United States, and in reservoirs in rural areas. Similar surveys Jiang, L., Sci Total Environ (1 Aug 2013); 458-460: 267-72.doi. Prevalence of antibiotic resistance genes and their relationship with antibiotics in the Huangpu River and the drinking water sources, Shanghai, China. have been carried out in rivers, lakes and reservoirs around the world with similar results. The higher the quantity and the wider the variety of drugs, the more Huerta, B., Sci Total Environ (1 Jul 2013); 456-7: 161-70. Exploring the links between antibiotic occurrence, antibiotic resistance, and bacterial communities in water supply reservoirs. resistant genes.

So no matter where you live or what you eat, you regularly get antibiotics with water.

Even bottled mineral water is unsafe, as most of the brands tested contain bacteria that, upon contact with antibiotics, have shown FalconeDias, M. F., Water Res (Jul 2012); 46 (11): 3612-22. Bottled mineral water as a potential source of antibioticresistant bacteria. resistance to many of them. The agricultural industry and government food and agricultural control agencies claim that the doses ingested are completely harmless. But what if these august agencies, free from "conflicts of interest" and solely concerned with your welfare, are still wrong? Can small doses harm us?

Our friend Marty Blazer decided to test this empirically, and his laboratory found out Blaser, M., Missing Microbes (Henry Holt, 2014). that mice, which were given even tiny subtherapeutic doses of antibiotics in the first days of life or throughout their life, gained twice as much weight and fat as normal mice, and their metabolism was disrupted. The content of the gut microbiota has changed significantly: there are more Bacteroidetes and Prevotella, and less lactobacilli. When antibiotics were stopped in the mice, the microbial composition began to shift closer to the control group, although its diversity remained reduced. But later, even on a similar diet, mice that had previously received antibiotics remained fat for the rest of their lives.

The results were even more striking when the antibiotics were combined with a high-fat diet rather than regular, healthy mouse food. Blazer's lab also found that antibiotics severely damaged the immune system. Changes in the microbiota disrupted normal signaling pathways, and genes that control the immune system and healthy gut mucosa were suppressed.

Wanting to prove that the results depended on changes in the gut microbiota, and not on some direct toxic effects of drugs per se, the research team transplanted microbes from the intestines of mice that received antibiotics into sterile mice. This gave a similar noticeable weight gain, which convincingly proved that the problem was the impoverishment of the intestinal flora, not antibiotics. Whether the animals received high or low doses of antibiotics, both groups experienced increases in natural gut hormones associated with obesity, such as leptin and gastrointestinal hunger hormone PYY, which is released after receiving signals from the brain. transit time of food and stimulate increased absorption of calories. This reminds us of the importance of the interaction between the gut and the brain that occurs all the time.

Today's children are forced to withstand a rapid onslaught of antibiotics, be it injections given to mothers before a caesarean section, short courses of treatment for mild infections, or antibiotics given in breast milk.

To this must be added some contamination of tap water and food, the consequences of which we cannot yet assess.

Antibiotic therapy can be the cause of many unrelated and unexpected health problems. So, recently it was discovered by Gendrin, M., Nature Communications (6 Jan 2015); 6: 592. Antibiotics in ingested human blood affect the mosquito microbiota and capacity to transmit malaria. that taking antibiotics increases the risk of spreading malaria and infections, because it favors the introduction of plasmodium in case of mosquito bites. Antibiotics may also be the missing factor (or rather, probably one of them) that explains the current obesity epidemic, and its causes originate in childhood.

Reducing the diversity of gut microbiota and a diet of processed foods, sugars and fats have joined forces to create a veritable epidemic of obesity. What's more, as we gain fat and pass on carefully selected fat-loving microbes to our children, a vicious cycle occurs: the next generation gets even more antibiotics and becomes the owner of an even poorer microbiota than we are. In other words, the problem of microbiota depletion is escalating with each generation. This explains why the observed effects and trends are exacerbated in children of obese mothers who themselves have a disturbed microbiota.

Given that antibiotics are so hard to escape, is there a solution at all? Perhaps if you, along with the whole family, retrain into vegans - New Age fans who eat only organic food and are fundamentally against any drugs, this will lead to some shift in the microbiota. However, consolidating public efforts to reduce the use of these drugs will have a much better effect.

Our children will benefit most if doctors are not forced to prescribe antibiotics.

It is clear that in critical cases you have to seek help, but in case of minor illnesses it is better not to run to the doctor, but to wait a day or two and see if everything goes away by itself. If people begin to realize that we all get sick sometimes, and agree to suffer an extra half day without medication, our microbes will definitely feel better. The authorities can help with this. For example, France between 2002 and 2006 was able to halt the flow of antibiotic therapy and reduce the frequency of prescribing antibiotics to children by 36%.

If we really need drugs, we should turn to the means of modern genetics and develop antibiotics with a more targeted effect, and not flood the poor microbiota with a rain of drugs. In addition to cutting down on meat consumption (or going organic if you can afford it), there is a need to lobby the government to cut subsidies for the production of antibiotic-laden meat commercially. Antibiotic resistance is growing at a high rate around the world, and soon there will be no cure for serious infections, so it is worth considering an alternative. Alternatively, you can try to use viruses that kill bacteria and are safe for people. And for this it is necessary to increase funding for research in this area.

Tim Spector is Professor of Genetic Epidemiology at King's College London. In his book, Myths About Diet, he explores various misconceptions about good nutrition and concludes that even eating less and moving more may not be the key to health and leanness. It's much more complicated. Based on the achievements of science, the author explains what role the individual characteristics of the organism play. First of all, the human microbiome.