According to an updated survey by World Health Organization (WHO), complications related to cardiovascular diseases killed approximately 17.7 million people across the world in 2015 alone. Currently the most lethal of all diseases, it is responsible for one out of every four deaths in the United States. To put an end to this frightening epidemic, scientists from Stanford University School of Medicine have come up with an unlikely solution involving light and photosynthetic bacteria.

As part of the research, the team injected these microbes into the hearts of rats suffering from some form of cardiac illness. Following that, they used concentrated beams of light to activate photosynthesis. The resulting increase in oxygen flow, the scientists explained, in turn facilitated heart function. Speaking about the breakthrough, which was recently published in the Science Advances journal, Joseph Woo, the head of Stanford Medicine’s Department of Cardiothoracic Surgery, said:

The beauty of it is that it’s a recycling system. You deliver the bacteria, they take up carbon dioxide, and with energy from the light, they form oxygen.

The researchers stumbled upon this ingenious treatment technique while looking for new ways to get oxygen delivered to the heart in cardiac ischemia patients. One of the initial approaches, Woo revealed, involved pureeing a mixture of spinach and kale, and combining it with cardiac stem cells in a Petri dish. It was later found that chloroplasts, the chlorophyll-containing cells that lend leaves their green color, are actually incapable of existing outside the mother plant cells. Woo added:

We thought there is an interesting relationship in nature. In nature, humans exhale carbon dioxide and plants convert it back to oxygen. During a heart attack, the muscle is still trying to pump. There’s carbon dioxide but no oxygen. We wondered if there was any way to use plant cells and put them next to heart cells to produce oxygen from the carbon dioxide… So we kept looking around.

Using specific strains of cyanobacteria, also known as blue-green algae, the scientists conducted the same series of tests to see if the photosynthetic cells were actually able to survive in a laboratory setup. These bacterial cells were then injected into rats with cardiovascular disease. The exposed hearts of these animals were then placed under a concentrated beam of light for up to 20 minutes, following which they underwent further analysis. The team went on to say:

It was a little bit pie-in-the-sky. But it worked really well… The group that received the bacteria plus light had more oxygen and the heart worked better. This is still very preliminary.

As pointed out by the scientists, the microorganisms managed to survive inside the murine hearts for approximately 24 hours. The animals, however, continued to exhibit cardiac improvements for nearly a month. At present, the team is trying to figure out how this treatment technique could be of use to humans. Before that can happen, they will have to develop a safe and efficient way to focus light on the human heart.

Source: Stanford Medicine