How You Can Help Fight Superbugs

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“As soon as antibiotics were discovered and developed for medical use, bacteria began the Darwinian ‘arms race’ that has been fought ever since.”  So wrote Steve Heilig in the most recent Journal of the San Francisco Medical Society, where he is a director. Due to overuse of antibiotics, “antimicrobial resistance has reached a crisis stage in human medicine.”  You are doubtless aware that doctors should not prescribe antibiotics for viral infections (colds and flu) unless there is good evidence of an additional bacterial infection.  You may not know that 70 to 80 percent of all antibiotics produced by U.S. companies are used in farm animals.  These animals are often penned in crowded, dirty conditions; they are fed low doses of antibiotics to prevent infections and promote growth.  Bacteria are killed by the low doses used, but some develop mutations that make them immune to the drugs.  These bacteria are passed on to the farmers, their contacts, and the consumer.  Thorough cooking can destroy them, but beware of cutting boards, knives, your hands, and ‘rare’ burgers. 

In a 1976 study, small amounts of tetracycline were given to a flock of chickens by a researcher.  He found that the chickens began to carry bacteria resistant to tetracycline and other antibiotics.  So did the farmers who tended them.  Based on this kind of evidence, in 1977 the FDA announced plans to ban the feeding of low doses of antibiotics to livestock.  However, there was strong backpressure from legislators and agribusiness, and the FDA failed to act on its own recommendation.  The American Academy of Pediatrics, the Centers for Disease Control, the National Academy of Sciences, and the World Health Organization had identified subtherapeutic use of antibiotics as a human health issue.  More than 30 years later, in 2011, the FDA reacted when sued by the Natural Resources Defense Council and other groups.  It revoked its 1977 recommendation (never implemented) and said a ‘voluntary effort’ would be more effective.  There is no evidence that this has worked.  Currently there are over 90,000 deaths per year due to antibiotic resistance.  The Centers for Disease Control are alarmed.  We all should be.

You may have heard of a dreaded bacterium called MRSA – methicillin resistant Staphylococcus aureus, which is found in the community as well as in hospitals.  MRSA related deaths in the U.S. have risen to over 19,000 per year. from antibiotic resistant bacteria.  In Iowa, large pig farms where 2000 pigs are confined shoulder to shoulder, nearly half of these animals carry MRSA according to a 2009 study.  Almost half the workers there carry MRSA as well.

Here’s news close to home – an Iowa pig farmer who used routine antibiotics joined Niman Ranch’s pork collective; he stopped confining his animals and using antibiotics. He found he had the same results as Danish farmers who banned subtherapeutic antibiotics in 2000.  Pork production rose, and the incidence of resistant bacteria fell dramatically in people and animals. 

What can we do to protect ourselves, our children and the public?  There is a microbiologist in Congress, Louise Slaughter, a Democrat from New York.  Every year she introduces a bill called The Preservation of Antibiotics for Medical Treatment Act. We should make sure our congressman, Jared Huffman, supports this bill.  We should refuse to buy or eat meat, poultry, eggs or fish treated with antibiotics.  If it is labeled organic, this is a given. Otherwise, ask the butcher behind the counter. Trader Joe’s shoppers answered a poll by Consumer Union; 69% wanted the store to stop selling meat raised on antibiotics.  The store has hedged on this; although they do sell some antibiotic-free meats, they “do not presume to make choices” for their customers. Bring up this issue when you shop there. Whole Foods does not sell antibiotic-raised meats.  While these personal choices can make the meat you buy more expensive, eating less of it, and using it as a condiment/flavoring for vegetables is a wise move.  When you eat out, ask about the source of the meat, be sure it is not too rare, or go vegetarian.  There is no conclusive proof as yet that taking a daily probiotic pill, or eating yogurt with live cultures is helpful, but some studies point in that direction.  I think it’s a good idea. 

Sadja Greenwood, MD   back issues at sadjascolumns.blogspot.com

Go to Health: Protect Your GI Tract!






There has been a lot of ‘stomach flu’ in our community this year – actually it is not flu, and is not caused by the influenza virus, which affects the respiratory system. We can call it gastrointestinal disease (the GIs) indicating that it affects the stomach and intestines. The most common cause of the GIs is the norovirus – a group of viruses that cause inflammation of the stomach and large intestine, leading to nausea, vomiting, diarrhea, stomach cramps, low grade fever, headache, muscle aches and fatigue. There is no specific treatment for this disease, but it is vital not to become dehydrated; if you are affected, drink water, diluted fruit juice, and clear soup with some salt or miso. You should recover in 3-4 days, but some cases have lasted longer. Babies and young children can get dehydrated fast – so contact your doctor immediately if your child has serious vomiting and diarrhea. People who are frail or have weakened immune systems should also see their doctor promptly. Prevention of norovirus infection includes avoiding people with the GIs – this virus is highly contagious from handshakes, air droplets, surfaces and food. Wash raw fruits and vegetables carefully. Although the virus is not always destroyed by heat, you should still cook food carefully and completely, and definitely stay away from raw oysters and ceviche if you are determined to avoid getting sick.






Bacterial contamination of food is another serious source of GIs, with resistance to antibiotics a growing problem. Three quarters of antibiotics used in the U.S. are given to animals, not people. They are given to sick animals, and to prevent healthy animals from becoming sick. Antibiotics are also given routinely, to stimulate growth, since animals given low doses of antibiotics grow more quickly on the same amount of food. However, bacteria in the intestines of these animals become resistant to antibiotics, and are excreted in waste. Entering water and soil, they are found on fish, fruits and vegetables. They colonize the GI tracts and skin of farm workers and food processors. They are found in animal meat. They spread to the human population, who may develop antibiotic-resistant infections.






The FDA, the CDC (Centers for Disease Control), and state public-health labs monitor chicken, ground beef and turkey, and pork chops at retail stores nationwide. The percentage of chicken contaminated with salmonella rose to 12% in 2011. More than a quarter of infected samples were resistant to at least five samples of antibiotics.






Here is what you can do: have thoroughly cooked meat and fish when eating out. Forget about medium rare hamburgers unless you are certain the meat is organic. Wash raw vegetables carefully before eating, and know where they were grown, to avoid contamination from nearby factory farming of animals. Avoid fast food restaurants with the exception of Chipotle Mexican Grill, which says it never sells meat from animals treated with antibiotics. Whole Foods makes the same pledge. Niman Ranch, Marin Sun Farms, Applegate organics, Rocky and Rosie chicken and some other companies are also antibiotic free. Organic poultry and meat is less likely to harbor resistant bacteria as organic standards ban meat and fish given antibiotics.






Elderly people in nursing homes are especially vulnerable to illness from antibiotic resistant bacteria. They can benefit – and people of all ages can benefit – from a daily dose of probiotic bacteria. These are healthy bacteria that will colonize your intestines with good organisms which help to fight off the resistant bacteria. Unsweetened yogurt with live cultures can help, but even more beneficial bacteria are found in probiotic capsules, which should be kept refrigerated. We have 3 or more pounds of bacteria in our colons, helping us by digesting fiber and creating important vitamins such as vitamin K and B12. They thrive on the residues of vegetables and fruits, with lots of fiber. These bacteria, and those on our skin, mouth, nose and ears, are called the microbiome. Take care of your microbiome, people!


Sadja Greenwood, MD , MPH

What Is the Microbiome?


Writing in The New Yorker on Oct. 22nd, Michael Specter explains the amazing new discoveries about the bacteria, viruses and fungi that colonize our bodies and affect our health. His article, Germs are Us, starts out with a discussion of the bacterium Helicobacter pylori (H. Pylori), found in the stomach of half the people on earth. While on the one hand it is a principal cause of gastric and peptic ulcers, and is associated with an increased risk of stomach cancer, its longevity in the human species, at least 200,000 years, makes it likely that it also plays a positive role in human evolution. Specter explains that we are inhabited from birth (the birth canal, mother’s skin, other people, all our surroundings) with a hundred trillion or more microorganisms. These microbes are in our mouths, digestive tracts, and skin – some 10,000 bacterial species, with a weight of about 3 pounds. They help us digest our food, manufacture vitamins in the colon (biotin and Vitamin K), and help our immune systems prevent infections. While the genes we inherit play a role in our health and disease, so does the microbiome. The human body can be seen more as a ‘vast, highly mutable ecosystem …. than like an individual assembled from a rulebook of genetic instructions’. Streptococcus mutans, in the mouth, is a principal cause of tooth decay, releasing acid when we eat sugar. Dentists are working on a number of measures to control this bacterium, including chlorhexidine and xylitol chewing gum. The bacterium Lactobacillus sakei may be capable of warding off sinusitis; this bacterium is destroyed by antibiotics. While antibiotics are ‘the signature medical achievement of the 20th century, and have saved millions of lives’, there is a downside to their use in terms of our microbiome. People without H. Pylori in their gut seem to be more sensitive to allergens, and are more likely to have had asthma as children. Children born by C-section lack many microbes transferred in the birth canal. Research from Finland and Germany indicate that these children may have more allergies. There is also a strong relationship between the presence of H. Pylori and two stomach hormones that control appetite. Ghrelin induces eating, and leptin suppresses the appetite. People whose stomachs have H. pylori have less ghrelin after a meal and stop eating; people without it may not get the message to stop and become obese. The reason that animals (poultry, cows and pigs) fed with antibiotics gain weight faster may have more to do with this mechanism than with treatment of illness. About 40% of children treated with broad-spectrum antibiotics develop diarrhea – and treatment with a probiotic (good bacteria for the gut) may prevent this disease. About 10% of people carry a bacterium called Clostridium difficile (C. difficile), which is normally held in check by other bacteria in the gut. When given antibiotics, people with C. difficile can develop severe, life threatening diarrhea and gut inflammation. Researchers are now using a technique called fecal transplant, in which they take intestinal bacteria from healthy donors and place them in the patient’s intestines. Cures have occurred with this treatment when nothing else has worked.






Specter ends his article with cautionary advice on probiotics, which he considers over-advertised without backup research. In the future we may know more about beneficial bacteria, but at present he thinks there is insufficient knowledge to say which bacteria should be used. After reading this, I did a search of current medical research on the use of probiotics. There are considerable findings on the use of beneficial bacteria to decrease antibiotic induced diarrhea, in decreasing childhood allergy, in improving the outcome of patients undergoing surgery for colon cancer, in vaginal infections in women, in the management of adult-onset diabetes, and in many other areas. My own conclusion is that a daily probiotic capsule from a reputable supplement company, with or without the ingestion of high-quality unsweetened yogurt, can help to prevent many gastro-intestinal infections. Use antibiotics when they are needed for serious bacterial infections, but always be mindful of your own beneficial bacteria.


Sadja Greenwood M.D., MPH back issues on this blog

Beneficial Bacteria in your Body

Microbiologists are excited about recent studies showing that the bacteria in our guts, throat, genital organs and on our skin can have newly discovered beneficial roles in health. We have some 500 different strains of bacteria in our intestinal tract; the average healthy adult carries about 5 pounds of them. From the mouth to the colon, they help us break down and digest our food and allow for its absorption. They also synthesize a range of vitamins, from the B group to vitamin K.

About 70% of our immune system resides in the lining of the gut; signals from good bacteria influence immune cell development and susceptibility to infections and inflammatory diseases. Researchers at the University of Pennsylvania have shown that when mice are treated with antibiotics to reduce numbers of beneficial bacteria, they have an impaired antiviral immune response and delayed clearance of systemic viruses or influenza in the airways. The researchers concluded that signals from beneficial bacteria stimulate immune cells in a way that is optimal for antiviral immunity.. This may be a way that good gut bacteria reduce your susceptibility to colds and flu.

The same researchers also looked at allergic lung inflammation, similar to asthma in humans, and found that mice given antibiotics had higher levels of basophils in their white blood cells, and elevated seum IgE – seen in allergic disease. Researchers at the University of British Columbia found that mice treated with the antibiotic vancomycin reduced the diversity of microbes in the gut and increased the susceptibility of the animals to experimentally induced asthma. They conclude that normal bacterial populations can positively influence the response to allergens in the environment, making inflammation and asthma less likely. The bacterial multitudes in our bodies may have functions never before appreciated.

Antibiotics are life-saving drugs in many situations, including streptococcal throat infections (that can lead to heart valve damage), bacterial meningitis, bacterial pneumonia, urinary tract infections, et al. The purport of this column is not to criticize their use when needed, but to underline the importance of beneficial bacteria in the gut.

Research on the ‘microbiome’ is a hot topic currently, with exciting implications for human health. Microbiome is defined as the totality of microbes in the body (bacteria, viruses and fungi), their genetic elements and environmental interactions. What you can do right now to keep your microbiome in good shape is to feed your helpful intestinal bacteria the right food. Sugary foods that are low in fiber allow the ‘bad’ microbes to thrive. Avoid them. Certain foods are known as ‘prebiotics’ can help our beneficial bacteria. Examples are whole grains, oats, bananas, garlic & onions, artichokes and asparagus. In addition, many people take a ‘probiotic’ supplement that contains beneficial bacteria, and also eat fermented foods such as yogurt, kefir, and sauerkraut. Make sure the yogurt you buy contains living cultures, and avoid ones that are sweetened – it’s better to add fruit yourself. You can buy probiotic capsules at many grocery stores. Look in the refrigerated section and keep the capsules refrigerated at home to preserve the life of the bacteria therein.

If you take antibiotics for a bacterial infection, it’s a good idea to take a probiotic to restore your beneficial bacteria. This may help to prevent serious diarrhea after antibiotic use, which can occur when bad bacteria such as Clostridium difficile take over. Wait at least 2 hours after taking the antibiotic, so it can be absorbed into your bloodstream, before taking the probiotic. If you have asthma, a probiotic supplement might help – talk to you doctor about this.

Sadja Greenwood, MD, MPH - back issues on this blog. Write me a comment, and I'll answer you.