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Artificial sweeteners are being added to a growing number of foods to reduce their sugar content while maintaining their appealing taste. But a growing body of research suggests these non-nutritive sweeteners may not always be a healthier and safer option. So, what is our best option if we want to enjoy sweet-tasting foods without the harms of eating sugar?

Artificial sweeteners were originally developed as chemicals to stimulate our sweet-taste sensing pathway. Like sugar molecules, these sweeteners act directly on our taste sensors in the mouth. They do this by sending a nerve signal to the body that a high-carbohydrate food source has been consumed, telling the body to break it down to use for energy.

In the case of sugar consumption, this also stimulates our dopaminergic system. This is the part of the brain responsible for motivation and reward, linked to sugar cravings. From an evolutionary perspective, this means we’re hardwired to seek out high-sugar food for a source of energy and to ensure our survival. However, excessive consumption of sugar is well known to lead to health problems, such as metabolic disruption which can cause obesity and diabetes.

Similarly, when artificial sweeteners, rather than sugar, cause this stimulation, there’s increasing evidence of similar metabolic imbalances.

This happens despite the fact that artificial sweeteners do not seem to stimulate the dopamine system.

Indeed, a study published earlier this year showed that within two hours of consuming sucralose (an amount equivalent to the sugar in two cans of soft drink), participants exhibited increased physiological hunger responses. The research measured blood flow to the hypothalamus, the region of our brain responsible for appetite control. They found that sucralose increased blood flow to this area of the brain.

Studies have also shown that sweeteners can stimulate the same neurons as the appetite hormone, leptin. Over time, this could cause our hunger threshold to increase – meaning we need to eat more food to feel full. This suggests that consuming artificial sweeteners makes us more hungry, which could ultimately make us consume more calories.

And it doesn’t stop with feeling hungrier. A large study, which was conducted over 20 years, found a link between sweetener consumption and greater accumulation of body fat. Interestingly, the study found that people who regularly consumed large amounts of sweeteners (equivalent to three or four cans of diet soda per day) had a nearly 70 per cent greater incidence of obesity compared to those who consumed minimal amounts of artificial sweeteners (equivalent to half a can of diet soda per day).

The study also considered this response to be independent of the amount of calories the participants consumed each day. To verify this, they reviewed food questionnaires to assess self-reported dietary intake. While self-reported consumption can have discrepancies, the study also used a coding nutrition data system to verify dietary intake. The results indicate that artificial sweeteners may be making us more likely to form fat in our body – regardless of what we’re consuming alongside the artificial sweeteners.

A study published earlier this month also found that daily consumption of artificially sweetened drinks positively correlated with the incidence of type 2 diabetes. But given these drinks contain a range of additives – including acidifiers, dyes, emulsifiers and sweeteners – it’s uncertain if this link can be entirely attributed to artificial sweeteners.

What you need to know

So, is it time to give up sweeteners completely? Maybe not. There are many studies which add to the controversy by showing that short-term substitution of sugar with artificial sweeteners reduces body weight and body fat.

Numerous studies have also shown that artificial sweetener consumption has no association with the development of diabetes or even with indicators of diabetes, such as fasting glucose or insulin levels. However, many of these studies were performed over relatively short time periods (up to 12 months) and only compared people consuming artificial sweeteners versus sugar. This makes it hugely confusing for all of us to know what we should do.

To address this, earlier this month, the Scientific Advisory Committee on Nutrition (SACN), which advises the UK government on nutrition, released a position statement on the use of non-sugar sweeteners. This was in response to the World Health Organization, which suggested that sweeteners shouldn’t be used as a means of weight control due to their low-level association with the risk of developing obesity and type 2 diabetes.

The SACN similarly concluded that non-sugar sweetener intake be minimised, especially for children. But they also stated that intake of sugars in general needs to be reduced. This is really at the heart of the issue. Artificial sweeteners may have significant negative health impacts, but are they as bad for us as sugar? The overwhelming literature on the negatives of excess sugar consumption currently suggests no – but our understanding of artificial sweeteners is still not as extensive as that for sugar.

We need more research on artificial sweeteners to better understand their effects. Work is currently ongoing to collate a database of all clinical trials investigating sweetener use. This will allow us to better understand the sweetener research landscape and highlight areas where more work is needed.

Until then, what should we do if we have a sweet tooth? Unfortunately, like everything with nutrition, it’s best to only consume artificial sweeteners in moderation.

There are no clear guidelines on the amounts of sweeteners we should or shouldn’t be consuming yet. But one of the guidelines from the recent SACN review is that the industry clearly label the amount of artificial sweeteners in food and drink. So hopefully it will be easier for us to make these choices in the future.

Havovi Chichger is a Professor in Biomedical Science at Anglia Ruskin University. Caray A Walker is a Senior Lecturer in Microbiology at Anglia Ruskin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Known as the microbiome, your gut is home to millions of bacteria and other microbes—both good and bad—and can influence your health in many ways. The key is to balance the ratio of good to bad bacteria within the gut microbiome. The "right balance" is different for everyone, as each person has their own personal microbiome profile that is initially influenced by several factors, including how your mother gave birth to you and whether you were fed infant formula or breast milk.1

What you eat directly influences the makeup of bacteria in your gut.2 A healthy gut helps keep chronic diseases like heart disease and cancer at bay, reduces inflammation, keeps your brain healthy and helps you maintain a healthy weight. A healthy microbiome can even help with depression.3

So how do you improve your own microbiome?

Eat more: probiotics, prebiotics, fiber, polyphenols and fermented foods.

Eat less: artificial sweeteners, red meat, processed foods and alcohol.

Here, we will explain probiotics and prebiotics and provide examples of which foods are the best for each.

Probiotics

Probiotics are the beneficial bacteria that live in your gut and can be found in fermented foods like sauerkraut, kimchi, miso and yogurt. Eating foods that are naturally rich in probiotics adds good bacteria to your gut. The most common types of good bacteria are Lactobacillus and Bifidobacterium, with each having its own specific strains. In addition to helping balance your gut bacteria and prevent chronic disease, probiotics can help if you have diarrhea, boost your immunity and keep your heart and skin healthy.

1. Sauerkraut

Sauerkraut is made from cabbage and salt. During the fermentation process, microorganisms eat the sugar present in cabbage and produce carbon dioxide and acids. The probiotics created during fermentation assist with digestion and add good bacteria to your gut. Try to make your own sauerkraut. Most store-bought sauerkraut is pasteurized, which kills bad bacteria as well as the beneficial bacteria created through fermentation.

One cup of sauerkraut has 4 grams of fiber, per the USDA.4 Probiotics in the gut use fiber as fuel.

Enjoy sauerkraut with grilled chicken, substitute it for pickles on a sandwich or burger, add it to potato salad, or put it on a cheese plate and serve your friends something good for their guts. Try our Sauerkraut & Sausage Casserole for a warm, comforting meal any night of the week.

Photo of a fork lifting some sauerkraut out of a jar — Abbey Littlejohn

2. Kimchi

Kimchi, also fermented cabbage, is the spicy Korean cousin of sauerkraut. The flavor can be enhanced by adding scallions, radishes and shrimp. Look for kimchi in the refrigerated section near sauerkraut, other Asian sauces and pickles, or better yet, make your own to maximize probiotic content.

Kimchi is delicious added to a fried rice bowl with veggies and an egg.

Photo of kimchi in a bowl — Abbey Littlejohn

3. Kefir

Kefir is like drinkable yogurt. It's made when kefir grains, which are colonies of yeast and lactic acid bacteria, ferment the sugars in milk, giving it a slightly thicker consistency and tart flavor. Like yogurt, kefir is packed with probiotics, as long as the store-bought brand you buy uses pasteurized milk before the fermentation process. Pasteurization before fermentation ensures kefir contains live and active probiotics when you consume it.

Buy plain kefir (instead of flavored) to skip added sugars, or make your own kefir. Due to fermentation, kefir has a slightly tart and acidic taste, making it a tasty addition to a breakfast smoothie instead of milk. Or try substituting kefir for milk in one of our overnight oats recipes for a healthy combo of probiotics and fiber.

Kefir being poured into a cup — Abbey Littlejohn

4. Kombucha

Kombucha is a tart, fizzy tea made by adding a SCOBY (symbiotic colony of bacteria and yeast) and sugar to green or black tea. It's then fermented for a week or more. During fermentation, alcohol and gases are produced, giving the kombucha natural carbonation. The amount of alcohol is usually less than 0.5% alcohol by volume (ABV)—and commercially prepared kombucha is required to keep it no higher than this amount (federal law states that any product with more than 0.5% ABV must be regulated and marketed as an alcoholic beverage). Pasteurization is used to limit alcohol content, which means commercial kombucha contains few, if any, probiotics. Some homemade kombuchas, however, have been found to have closer to 2% to 3% ABV.

To keep the alcohol levels down on your homemade kombucha brew, make sure to keep it cold and refrigerated and shorten the fermentation time. You could also try using a different type of tea. Research has found that kombucha made with rooibos tea had lower ethanol (a type of alcohol) and acetic acid (aka vinegar acid) concentrations compared to kombucha made with black or green tea.5

When fermenting tea, lactic acid bacteria are produced, which are known to function as a probiotic. When consuming kombucha made from green tea, you'll also get the antioxidant properties associated with tea. Keep in mind that some kombuchas, like those made from black tea, contain caffeine. Others have artificial sweeteners, which can negatively alter gut bacteria (and defeat the purpose of drinking it), so read labels—or make your own.

It's important to note that kombucha is not recommended for people with compromised immune systems or if you're pregnant or breastfeeding. This is partly due to the alcohol content (small as it may be), and because many commercial brands are not pasteurized and could potentially cause illness. Kombucha is also not recommended for children.

Photo of 3 jars of kombucha in different colors red, orange and yellow — Abbey Littlejohn

5. Miso

Miso is a fermented paste made from soybeans, barley or rice. Similar to other fermented foods, beneficial bacteria are produced in the fermentation process. You'll also get some protein if you eat miso made from soybeans. A little bit goes a long way, which is good since miso is also high in sodium.

Miso is great when added to sauces, dressings and soup bases. Try it on this Miso-Maple Salmon.

Photo showing a container of miso with a spoon in it. — Abbey Littlejohn

6. Tempeh

Tempeh is similar to tofu in that it's made from soybeans, but unlike tofu, tempeh is a fermented food, so it contains probiotics. Tempeh is made when soybeans are fermented and then pressed into a cake. It can then be grilled, sautéed or baked. Tempeh is high in protein, making it a good option for vegetarians and vegans. It's also packed with B vitamins, calcium, manganese, zinc and copper.

Try marinating then grilling tempeh and adding it to a salad. Or make Gochujang-Glazed Tempeh & Brown Rice Bowls.

Photo of tempeh sliced on a cutting board — Abbey Littlejohn

7. Yogurt

Yogurt is probably the most popular probiotic and for a good reason. It's made when good bacteria are added to milk, where they metabolize lactose to form lactic acid and other beneficial microbes. Look for yogurt labeled with the "Live & Active Cultures" seal, which guarantees 100 million probiotic cultures per gram at the time it was manufactured. A quick look at the ingredients list will also show you if there are bacteria in the yogurt. Do you have trouble digesting lactose? The probiotics in yogurt help digest some of the lactose (milk sugar), so if you're lactose intolerant, you may be able to enjoy yogurt—and kefir. If you don't eat dairy, many companies now make dairy-free and vegan yogurts that contain probiotics. Or you could make your own Instant Pot Cashew Yogurt.

Photo of yogurt with a spoon in it — Abbey Littlejohn

Prebiotics

Pictured Recipe: Muesli with Raspberries

When you're trying to establish more probiotic bacteria in your gut, you need to feed them with prebiotics so they can flourish and keep making more good bacteria. "Prebiotics are fibers that feed the beneficial probiotics in your gut," says Dianne Rishikof, M.S., RDN, LDN, IFNCP, a registered dietitian, integrative and functional medicine nutritionist and president and CEO of Health Takes Guts, a nutrition counseling private practice. "Ingredients to look for include galactooligosaccharides, fructooligosaccharides, oligofructose, chicory fiber and inulin." Fructans and cellulose are two other prebiotic fibers.

But don't get bogged down in the scientific names. In fact, you won't see most of these compounds listed on a label because they are present in foods that don't have labels—like fruits and vegetables.

Focus on a variety of whole foods. "It's all about diversity, getting as much variety of plant-based foods as possible and hitting our recommended fiber intake of 30 g per day," says Megan Rossi, Ph.D., B.H.Sc., RD, APD, founder of The Gut Health Doctor. Apricots, dried mango, artichokes, leeks, almonds, pistachios and legumes, as well as polyphenol-rich foods, such as blueberries, strawberries, prunes, apples, flaxseed, olives and extra-virgin olive oil, are extra-high in prebiotics, Rossi writes in her book, Love Your Gut.

8. Jerusalem Artichokes

Though commonly referred to as Jerusalem artichokes, this tuber isn't an artichoke at all but rather a part of the sunflower family. Also known as sunchoke, sunroot or wild sunflower, they look similar to gingerroot. One cup of Jerusalem artichokes delivers 2.4 g of fiber, per the USDA.6 Research has indicated that 80% or more of the carbohydrates in sunchokes is inulin, a prebiotic fiber that provides food for your gut bacteria.7

Try sunchokes roasted with olive oil and garlic or raw in salads (they have a texture similar to water chestnuts).

Photo of Jerusalem artichokes with one being sliced on a cutting board — Abbey Littlejohn

9. Leeks

Leeks are high in good-for-the-gut fructans. According to the USDA, 1 cup of leeks has 1.6 g of fiber and just 54 calories.8

Leeks can enhance nearly any dish—consider adding them to an omelet or sautéing them to mix with roasted potatoes. Alternatively, rub whole leeks with oil and grill briefly; then toss with your favorite vinaigrette. Try our Sesame-Braised Leeks that require only 10 minutes of prep.

10. Onions

Onions are chock-full of inulin, fructans and fructooligosaccharides (FOS). Not only do FOS prebiotics help build up gut flora, but they also help to improve a plethora of conditions, including diarrhea, osteoporosis, atherosclerosis, gastrointestinal disorders, cardiovascular disease and type 2 diabetes.9

Onions are highly versatile: Add to soup or salad, grill and put on top of a turkey burger, or roast with herbs and serve as a side.

Photo of onions and shallots — Abbey Littlejohn

11. Raspberries

According to the USDA, 1 cup of raspberries has a whopping 8 g of fiber, about one-third of your Daily Value (DV).10 Raspberries are a rich source of polyphenols, potent antioxidants that your gut microbes love to nosh. Polyphenols act as prebiotics by enhancing the growth of beneficial bacteria and inhibiting the growth of pathogens.11

Raspberries are delicious when eaten fresh but are just as nutritious purchased frozen and thrown into a smoothie. Or add them to yogurt, oatmeal or high-fiber cereal.

Photo of raspberries in a blue and white bowl — Abbey Littlejohn

12. Beans and Legumes

Many steer clear of beans for fear of having gas, but flatulence can be a sign that your gut bacteria are hard at work. When the fiber in beans and legumes, such as black beans, chickpeas, peas, lentils and white beans, reaches the large intestine (colon), it's still intact. It's there that gut bacteria feed on them. This process is called fermentation. And the byproduct may be some gas.

Canned beans are a favorite—pick three types, rinse and mix for a simple bean salad. Or throw black beans on top of tacos. Lentils are delicious in soup—even dried lentils take only 15 to 20 minutes to cook, so they make for a quick and easy add-in for your favorite soups and stews.

Photo of beans, peas, chickpease and lentils in different bowls — Abbey Littlejohn

13. Asparagus

Asparagus is a powerful prebiotic for the gut due to its level of fructans (inulin and FOS). Asparagus is also loaded with antioxidants, natural chemicals that fight off free radicals and other inflammatory compounds in the body.

Roasted asparagus can be made in just 15 minutes—simply toss the spears with olive oil, salt and pepper and oven-roast at 400°F for 10 to 15 minutes. Or shave raw asparagus over a green salad. Asparagus is also delicious when added to pasta or an omelet.

Photo of asparagus on a plate — Abbey Littlejohn

14. Garlic

As part of a healthy diet, garlic is anti-inflammatory in the body. Inulin and fructooligosaccharides are the two main fibers in garlic—a dynamic prebiotic duo. But that's not all garlic is good for. Garlic also has shown positive health effects regarding cancer, cardiovascular disease, metabolic disorders, blood pressure and diabetes, thanks to its antioxidant, anti-inflammatory and lipid-lowering properties. That's a whole lot of benefits in those little cloves!

If you don't like messing with peeling garlic cloves (and the smell it leaves on your hands), a good garlic press is invaluable. You can put the whole clove in there without having to peel it (yes, please!). Garlic can be used to season almost any dish. Sauté it with onions and mix it into a stir-fry or pasta.

Photo of garlic on a cutting board — Abbey Littlejohn

15. Bananas

Green bananas (the unripe ones) are best for the gut because they contain resistant starch, a type of indigestible fiber that produces more beneficial bacteria when your microbes feed on it. Ripe bananas are full of fiber too, which helps keep you fuller longer.

Eat bananas with peanut or almond butter for protein, healthy fat and an extra dose of fiber. Add them to overnight oats, Greek yogurt or a high-fiber cereal, or use them as a topping for whole-wheat toast.

Photo of banana slices in a bowl with a whole banana nearby — Abbey Littlejohn

16. Pears

Pears are a prebiotic food for the gut and also contain pectin, a type of fiber that helps lower cholesterol. One medium pear is just 100 calories but has 5.5 g of fiber, according to the USDA.12

Add a dash of cinnamon to fresh pear slices for a tasty snack, bake a pear crisp or mix diced pear into oatmeal for additional cholesterol-lowering benefits, thanks to the fiber in oatmeal, known as beta-glucan.

Photo of pears with one sliced open — Abbey Littlejohn

17. Watermelon

Watermelon is naturally high in fructans. According to the USDA, 1 cup of this juicy fruit is also 91% water by weight and adequate fluid is necessary to help fiber prevent constipation and keep the gut functioning.13

Watermelon is a summer staple that is tasty eaten plain. Find that boring? Make a refreshing beverage with it as we do in our Watermelon-Basil Agua Fresca or combine it with feta and mint for a summery salad.

Photo of watermelon slices — Abbey Littlejohn

Polyphenols

"Polyphenols are a type of plant chemical that gut microbes love," says Rossi. They are found in berries, apples, artichokes, red onions, tea, dark chocolate and other fruits and vegetables. Gut bacteria feed on polyphenols and produce beneficial substances, which, in turn, have a positive influence on certain conditions, including cancer, diabetes, cardiovascular diseases and aging.14