Hundreds of species of fish are ingesting plastic, including some that humans eat, a newly published study found. The team of researchers, which did a review of the growing scientific literature on this topic, found the amount of plastic that ocean fish consume is rising as well. There is already evidence that microplastics in fish stomachs migrate to muscle tissue, which people eat. "'Out of sight, out of mind' is not an effective response to ocean pollution – especially when it may end up on our plates," they write.

Data show that Pfizer’s COVID-19 vaccine is effective in obese people, but concerns remain. Obesity medicine physician Cate Varney from the University of Virginia writes that previous studies showed flu shots are less effective on people who have excess weight or are obese. Pfizer’s clinical trials for the COVID-19 vaccine included obese people, which provides some comfort that it provides protection, but there are questions over how long it will remain effective, she explains.

Microbes in your gut can influence how well drug therapies work. Scientists transferred fecal matter from melanoma patients who responded well to immunotherapy to patients for whom those therapies failed and saw an improvement post-transplant. The experiment was designed to test whether the health of a person’s microbiome – the trillions of bacteria in our digestive tract – can boost a cancer patient’s immune response and the effects of drugs. Medical oncologist Diwakar Davar from the University of Pittsburgh explains the results of the trial and the broader link between disease and the microbiome.

See our full list of the latest science and research news below. There’s also a link to our weekly podcast featuring a story on the three missions to Mars that are all arriving this month.