TOPSHOT - A diver photographs golden anthias (Pseudanthias aurulentus) on a coral reef in the ... [+] Egyptian Red Sea marine reserve of Ras Mohamed (Photo by EMILY IRVING-SWIFT / AFP) (Photo by EMILY IRVING-SWIFT/AFP via Getty Images)AFP via Getty ImagesAccording to the National Center for Complementary and Integrative Health, about four million American adults take probiotic dietary supplements to help with matters like digestion, allergic reactions, and mental acuity. Probiotics are like good guy bacteria helping fight bad guy germs, which they do by re-seeding an individuals microbiome. (That's the community of necessary bacteria, fungi, and viruses that live in or on bodily tissue and fluids and that help humans maintain general health.) Dietary supplements are not the only way for humans to ingest probiotics. Yogurt, kefir, and fermented vegetables, for example, contain plenty of them. This means that most people do not need to spend grocery money on probiotic pills. Still, supplements can often help people whose physiology is stressed.Surprising new research from an international team of scientists suggests that even coral reefs that are stressed can benefit from probiotic supplements. Coral Reefs Are Kind of Like Russian Nesting DollsInside coral reefs are communities of tiny, soft-bodied animals called polyps. Tentacled, theyre related to anemones and jelly fish. Although polyps are usually transparent and without color, inside each one live millions of brilliantly hued, microscopic algae. The relationship between the polyps and the algae is symbiotic. Polyps supply algae with compounds that they need in order to photosynthesize. Algae give coral color as well as amino acids, glucose, and glycerol. Polyps use the chemical compounds to make proteins, fats, and carbohydrates. To summarize the geometry: Inside the reefs live polyps. Inside the polyps live microscopic algae that give polyps food and vivid color.Reefs Are Multi-Unit Housing Complexes Made of ExoskeletonsPolyps extract calcium and carbonate ions from the sea water surrounding them and use the ions to make exoskeletons of calcium carbonate (limestone). The exoskeletons are rigid, cup-shaped encasements that polyps secrete from the bottoms of their anatomy and then sit inside. The exoskeletons are key to the life of coral reefs. Indeed, they are the reefs. When hundreds of thousands or even millions of exoskeletons meld together they can weigh several tons. TOPSHOT - A bommie reef in the Egyptian Red Sea marine reserve of Ras Mohamed, off the southern tip ... [+] of the Sinai peninsula. (Photo by EMILY IRVING-SWIFT/AFP via Getty Images)AFP via Getty ImagesIn addition to keeping polyps safe, reefs provide hiding places as well as grazing and hunting grounds for a wide variety of marine life, and so are important to the health of oceans in general. Why Reefs BleachWhen stressed by factors like high water temperatures or loss of light or nutrients, polyps cant physiologically support the algae living inside them. As a result, they expel them. With the algae gone, the polyps lose color and so do the reefs. (Limestone is white. It is polyps reaching out from their homes that embue the reefs with hue.) Bleached coral reefs arent necessarily full of dead polyps, but they are full of physiologically imperiled ones. Unfortunately, over recent decades coral reefs have been under unprecedented stress from global warming. As reefs bleach and then die, the hiding and feeding sites of thousands of fish and other marine animals disappear. Probiotic Treatments for Bleached CoralIn much the same way that the health of an individual human depends on his or her microbiome, the health of every component of a coral reef, from the limestone down to the algae, depends on communities of bacteria, fungi, and viruses. New research conducted by an international team of scientists and published in the peer-reviewed journal Science Advances demonstrates that at least one kind of coral reef can gain an assist from probiotic treatment just the way some humans do. In this new study, beneficial microorganisms for coral (BMC) treatments were used to rescue polyps and reefs from the effect of drastic temperature increases. MALDIVES, INDIAN OCEAN - APRIL 2017: Panoramic view of a diver swimming over a coral reef with most ... [+] of the corals are dead on April 11, 2017, Maldives, Indian Ocean. (Photo by Alexis Rosenfeld/Getty Images)Getty ImagesThe scientists worked with a species of coral called Mussismilia hispida, which they gathered in 80 fragments from the Atlantic Ocean off of Brazils coast and placed in an aquarium that mimicked natural conditions. The team caused bleaching in the fragments by incrementally raising water temperatures from about 26 degrees Centigrade to 30 degrees over the course of eight days. They maintained the elevated temperature for ten days and then incrementally over four days returned the temperature to 26 degrees. After that, the temperature was held stable for a recovery period of 23 days. Before and during the temperature increase as well as during temperature decrease and the recovery period, one group of coral was treated regularly with BMCs consisting of six different bacterial strains. Coral fragments in a control group were treated with a saline solution placebo.  All of the coral that had been treated with BMCs survived the bleaching event. As Raquel S. Peixoto ofthe Federal University of Rio de Janeiros Institute of Microbiology and Saudi Arabias Red Sea Research Center at King Abdullah University of Science and Technology explained in an email Probiotics not only ameliorated bleaching but also (and actually!) prevented coral death. Whereas 100% of the BMC-treated coral fragments survived, only 60% of the fragments treated with placebo did.  Not surprisingly, the team of scientists has suggested that, with global warming and the increasing frequency and severity of ocean warming events, a novel intervention like probiotic inoculations might put a halt to coral die-offs and to what they suggest should be called post-heat stress disorder. If probiotic inoculations work, it could save not just coral but the many thousands of marine animals that depend on reefs for grazing, safety, and hunting grounds.An enormous challenge yet to be solved, however, is how to inoculate reefs on a mass scale in nature. In her email Peixoto suggested, We have several strategies, some being worked on in collaboration with engineers and involving robots and artificial intelligence as well as the development of slow-release delivery systems. These might include bacterial pills that could slowly release bacteria onto corals for 20-30 days. With an approach like that, we might only need to inoculate the reef from one to three times during a bleaching event. Our idea would be using National Oceanic and Atmospheric Administration (NOAA) bleaching alerts to know when and where a bleaching event would happen and then inoculate the reef just before and during the event.As Peixoto also explained, the clock is ticking for coral reefs. Whatever approach scientists test and select, they need to act quickly. The investigative team was Erika P. Santoro, Ricardo M. Borges, Josh L. Espinoza, Marcelo Freire, Camila S. M.A. Messias, Helena D. M. Villela, Leandro M. Pereira, Caren L. S. Vilela, João G. Rosado, Pedro M. Cardoso, Phillipe M. Rosado, Juliana M. Assis, Gustavo A. S. Duarte, Gabriela Perna, Alexandre S. Rosado, Andrew Macrae, Christopher L. Dupont, Karen E. Nelson, Michael J. Sweet, Christian R. Voolstra, Raquel S. Peixoto.