Record numbers of Americans got flu shots during the 2013 flu season last year — almost 35 percent of all adults. (Each year, between 5 percent and 20 percent of Americans catch the flu, and while it always causes discomfort, it can also cause more serious health complications, and in rare cases, death in vulnerable people.)

With the exception of those people who have egg allergies (albumin, from eggs, is used in the shots), most doctors advise that we should all get a flu shot (of course, check with you health care provider). "Everyone 6 months of age and older should receive a flu vaccination," Dr. Howard Koh, assistant secretary for health at the U.S. Department of Health and Human Services, said in a news conference last fall.

So, if you've decided to get a flu shot this year, there are a few ways to make sure that it's as effective as possible.

Get better gut bacteria: According to a study on mice from Emory University, those treated with antibiotics either before or during the time they got the flu shot may have a weaker response to the vaccine. In the study, published in the journal Cell, researchers wrote in their abstract: "These results reveal an unappreciated role for gut microbiota in promoting immunity to vaccination."  

When you take a course of antibiotics, they kill beneficial bacteria along with the bad guys that might be giving you trouble in the form of an earache, strep throat, or a skin infection. But those good bacteria are important. 

"Our results suggest that the gut microbiome may be exerting a powerful effect on immunity to vaccination in humans, even immunity induced by a vaccine that is given at a distant site," Bali Pulendran, professor of pathology and laboratory medicine at Emory University School of Medicine told Futurity.

How does this translate to what you do? If you are taking antibiotics, it's always a good idea to supplement with probiotics (either in pill form, or via foods like yogurt) both while you are taking the meds — take your probiotics at alternate times, not the same time as antibiotics — and after you are done taking them. You can also eat foods that support healthy gut bacteria, like fresh fruits and vegetables, and high-fiber grains. 

The upshot of cultivating healthy bacteria in your digestive tract is that studies have found that will boost your immunity to illnesses of many kinds, including colds and flu. 

Move that body: Exercise — even just one bout, on the day you are vaccinated — can boost your immune response. In studies where weight-training exercise happened before a flu shot — and in another where cardio was done after — more antibodies were produced. A study in the Journal of the American Geriatric Society found in a 10-month controlled human trial that "regular endurance exercise improves influenza vaccine responses."

Regular exercise also has a positive effect on longer-term immunity as well, meaning that regular workouts can boost the efficacy of your flu shot even months later: "The peak antibody response wasn't that much higher in exercised individuals, but antibody response did not decline as rapidly in exercising adults," Marian Kohut, an Iowa State University professor of kinesiology, told the Iowa State News Service when explaining the research that she and her team had done. "So, if there was a flu outbreak in April, and you received your flu shot in early October or late September, those who exercised might be better protected at that point than those who didn't.

"But since getting people to exercise regularly is such a struggle, going for a walk or doing modest exercise after your flu shot — just once — might be a more effective measure to boost protection," Kohut said.

Get a higher-dose flu shot: A new study, published in the New England Journal of Medicine, has found evidence that, among the over-65 population included in a study of more than 30,000 Americans and Canadians, a higher-dose flu shot conferred a 24 percent reduction in flu cases. "Among persons 65 years of age or older, IIV3-HD [high-dose vaccine] induced significantly higher antibody responses and provided better protection against laboratory-confirmed influenza illness than did IIV3-SD [standard dose vaccine]," the authors of the study wrote.   

There are anecdotal reports that the response to the higher-dose flu shot might be more severe (indicating a stronger immune response from the body), so as with any time you are getting a shot, be sure to speak with your doctor about what's right for you. 

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Starre Vartan ( @ecochickie ) covers conscious consumption, health and science as she travels the world exploring new cultures and ideas.