A Bacterial Lunch

The secrets to weight loss may not lie on strange synthetic chemicals or unhealthy new fad diets, but actually in some simple bacteria we’ve known for as long as we’ve been born.

The bacteria in our intestines help us digest the food we intake; from carbohydrates to proteins to fats. But there’s something we humans can’t actually digest: fibre, so instead we use it to push the rest of the food through our guts and prevent constipation. However, since we should eat plenty of fibre, some bacteria use the excess and digest it too, and when doing so, release a substance scientists call propionate. This chemical triggers a reaction in our cells which results in them releasing a specific type of hormones: satiety hormones, such as PYY and GLP-1. As their name suggest, they are used by the body to make people feel ‘full’, by sending messages to the brain telling it to stop eating. In people, it usually takes a decent amount of fibre to trigger this response, so the person has to ingest a large amount of food before this reaction happens.

bacteria lunch

Don’t they look delicious?

But in developed countries, there is an excess of food, so people over indulge and end up over weight or obese. To stop this, scientists have been working with these bacteria in our guts and have come up with a possible solution.

In the form of IPE (inulin-propionate ester), propionate is in a concentration 8 times as large as that of a normal dinner, high enough to trigger the “I’m full” response despite not eating enough fibre. In theory, if a person takes this at some point during the day, they will produce the satiety hormones that will tell the body they are full so the person won’t feel the impulse to eat. The objective of the drug is therefore to reduce weight gain by reducing food intake.

To test this drug, some interesting experiments were carried out. The most curious one consisted of having two groups of people: one taking IPE and one not (the control) face a buffet and an open invitation to eat as much as they wanted (a.k.a. heaven). People with IPE in their system ate 14% less than those without IPE. And if the drug was given to people leading normal lives for six months, those taking the drug ate on average 9% less than those with no drug.

So although eating bacteria’s remains doesn’t sound like the most appealing plate in the book, it could produce long-term improvements in our health.


The Potato Controversy

Genetically Modified food has been controversial for many years now, and has a long history of arguments between food manufacturing companies and people against ‘unnatural’ food. The new chapter in this story involves none other than a potato.

Simplot, a company known for its normal and genetically modified potatoes, has created a new product which they call ‘the Innate Potato’, because of how natural it is compared to other GM crops.

To make this potato novel and unique in the GM market, Simplot has created it using RNA interference technology. This method uses RNA strands from other potatoes with different characteristics and mashes them together, to create a sort of Frankenstein Monster potato. The result is much more appealing than the name suggests. By combining many positive qualities from different potatoes, you end up with a potato with numerous benefits. This particular potato, for example, has proven resistant to bruises, and produces fewer carcinogens when fried. Usually, when normal potatoes are fried, the amino acid asparagine can react to form acrylamide, a suspected carcinogen. When tested, Innate Potato produced up to 75% less acrylamide when heated.


Someday in the future, it is possible that McDonalds fries are made from genetically modified potatoes

Not only that, but since it only uses genes from natural potatoes, and doesn’t use genetic material from other species like bacteria, it is immune to many of the usual complaints of GM-haters, which dislike the idea of mixing genes between two opposite species.

In spite of the strong opposition, the Innate Potato has already been approved by the USDA, (the Unites States Department of Agriculture), so it could potentially be sold to customers anytime now. In fact, rumour has it that McDonalds, one of Simplot’s biggest customers, might use the potato in the near future to make their well-known McFries. This, of course, has caused a heated debate where some opposers of these potatoes are pressuring the fast food company to reject them. McDonalds’ decision concerning this matter is still unknown.

However, Simplot only plans to grow a limited number of these super potatoes for now, so regardless of McDonalds’ decision we’ll probably have to wait quite some time to taste them.

Until then, McFries are still delicious.

Superhero Chloroplasts

This week, I bring you another plant-related article, this time discuss how scientists are trying to upgrade the photosynthetic process in plants.


A chloroplast, which, in the future, could be filled with honeycomb-like structure called carboxysomes

It has been a billion years since an eukaryote ingested a chloroplast and by accident created the essential symbiotic relationship to which we owe all the energy by which we survive. However, the way chloroplasts work hasn’t really changed in all these years, even though the environment has, and its system is quite obsolete. On the other hand, the descendants from the species of the first chloroplast, the cyanobacteria, have really changed their photosynthesis, which is much more efficient than that of chloroplasts.

The main difference between our world and the world a billion years ago, at least for this topic, is CO2 and 02 levels in the atmosphere. Before, there was an enormous amount of carbon dioxide in the atmosphere, which cyanobacteria and chloroplasts could exploit to produce food by photosynthesis. But as plants became more abundant, they absorbed the CO2 and released 02 , giving rise to our current balance of elements in the air. The most favourable conditions for a fast photosynthetic rate are high levels of CO2 in the air but since this is not the case anymore, there is a need for some changes in the organisms themselves. Plants, which have remained mostly unchanged, have reduced their efficiency, whereas cyanobacteria, which have evolved, actually improved it. The key to their success lies in their ability to maintain high levels of CO2 within the cell, thanks to carboxysomes. These are tiny, regularly-shaped compartments that fill the bacteria, and are specialised in maintaining CO2 trapped in them, so there is more of it available for photosynthesis. They even have protein pumps in their membrane which actively pumps CO2 into the cell.

This unique mechanism is what scientists are now trying to copy into a normal plant chloroplast. To do so, they would use genetic engineering: adding genes from the marvelous cyanobacteria to the chloroplasts so they would develop the pumps, which could increase efficiency between 15-25%; an outstanding upgrade. Transferring the carboxysome technology would be a bit more complicated, requiring more genes and the knowledge on how to make the structure itself, which at the moment is lacking.

Still, this innovative improvement offers an immense upgrade, which would sure be useful to farmers and food suppliers, who have found a rapid increase in their customer pool but a slow increase in their yield, a problem which could be remedied if this solution worked.

As always, there is some opposition, arguing that if plants have evolved for millions of years and have never developed a new way for photosynthesis to occur, there must be a reason for a reason, so natured shouldn’t be tinkered with. The pros and cons for this situation are many, and it is a subject which divides the scientific community.