Hello Nature readers,
Today we discover how a high-fibre diet was able to fix a disrupted mouse gut microbiome, learn about an unprecedented collaboration between an Indigenous tribe and a genomics lab and marvel at the month’s best science images.

The month’s best science images

These illustrations offer ways to visualize mathematical functions known as isogenies. The images, which describe an object called a supersingular elliptic curve, won cryptography researcher Ryan Rueger a distinction at Swiss National Science Foundation’s 2025 scientific image competition.

See more of the month’s sharpest science shots, selected by Nature’s photo team.

How to fix a gut microbiome

A low-fat, high-fibre diet might be able to replenish gut microbes that have been ravaged by antibiotics. A study in mice found that this diet was better at restoring the microbiome than transplanting faeces — and the microbes it contains — from a healthy gut into a disrupted one. An unhealthy diet also rendered such transplants ineffective at helping the gut recover. “It’s a bit of wishful thinking to believe that [a faecal transplant] can be a quick fix,” says microbiome researcher Marie Joossens. “Nutrition plays such an important role.”

Exclusive: NIH to suspend research abroad

A forthcoming policy from the US National Institutes of Health (NIH) will target — and at least temporarily halt — funding to laboratories and hospitals outside the United States. The move threatens thousands of global-health projects on topics from emerging infectious diseases to cancer. The NIH plans to release the policy in the next week, but it is currently unclear when it will take effect and whether it applies to all non-US institutions. “These decisions will have tragic consequences,” says former NIH director Francis Collins.

Genomics confirms Chaco Canyon DNA link

Members of the Picuris Pueblo tribe have worked with one of the world’s leading ancient-genomics labs to find genetic evidence linking their people to ancient inhabitants of Chaco Canyon, around 275 kilometres west of their modern-day base near Taos, New Mexico. The project, initiated by Picuris Pueblo leaders, offers a model for equitable collaborations between Indigenous communities and scientists, say participants. Craig Quanchello, the Picuris Pueblo lieutenant governor and a study co-author, hopes the findings will help convince people — including the US government — that his tribe deserves a say in Chaco Canyon’s future. “We’ve been telling our stories since time immemorial, but this is something on their terms that they can understand,” says Quanchello.

New technique cleans up nickel refining

A new method for refining nickel could slash the enormous carbon footprint of the processes — currently equivalent to that of a small country — by more than 80%. The new method uses hydrogen plasma to extract oxygen from ores called laterites, which produces a high-purity mix of iron and nickel plus a little magnesium. Implementing the process on an industrial scale would present some engineering challenges, but “what we did here is to prove that the science works”, says metallurgical engineer and study co-author Ubaid Manzoor.

How governments can help people thrive

To guide policies that help their citizens flourish, governments should establish systems for collecting robust data on people’s well-being, say epidemiologist Tyler VanderWeele and social scientist Byron Johnson. Early results from the Global Flourishing Study, which aims to address some of the issues in current data collection on flourishing worldwide, offer an example of the insights this kind of data can yield. For example, in many countries, flourishing tends to increase with age, which suggests policies that enable younger people to flourish would be beneficial, the authors write.

Live subtitles are transforming hearing loss

Improvements in hearing aids, cochlear implants and treatments in past decades means “there is no better time in all of human history to be a person with hearing loss”, in the words of one researcher. But many people who have hearing problems say that advances in speech-to-text transcription are an unsung breakthrough. A post-pandemic boom in working from home, where people can control noise levels and take advantage of captions on video calls, has also been a boon. Now engineers are merging sight and sound with glasses that subtly display transcriptions of everyday life. And you don’t have to have hearing loss to enjoy the advantages of reading along — after all, Netflix says that more than 80% of its viewers use subtitles at least once a month.