We're still in the middle of the winter season, which means an ongoing battle with dry skin. Humidity is at its lowest, and the temperatures fluctuate way too fast before you can adjust to either environment: the freezing weather outside or the blasting heaters indoors.

This lack of moisture and constant change takes a serious toll on your skin. You experience tightness, redness, flaking, itchiness yes, we've all been there. There's really no better time than now to call in the reinforcements and get back that healthy glow. And we've got the answer for you: probiotics.

One of the best ways to defeat dry, stressed-out skin is by adding probiotics into our skin care routine and diet. Just as oral probiotics can help balance the microflora in our digestive system, scientific studies have shown that applying topical probiotics can be hugely beneficial too.

Surprised? Here's How It Works.

There are both good and bad bacteria living in and on our bodies. Probiotics are the good kind that help maintain total body wellness like keeping the gut healthy and improving skin health. One of the ways probiotics repair and moisturize our skin is by helping produce hyaluronic acid (HA), which is a natural substance our body produces and is a major contributor to the elasticity, tightness, and strength of our skin.

Benefits from Bacteria

When the production of HA increases, our skin becomes more hydrated. In addition to preventing the loss of hydration, probiotics strengthen our skin so that it can act as a physical barrier to the negative effects of winter by keeping out pathogens, bad bacteria, pollution, and other toxins. This also helps keep hydration in our skin so it doesn't evaporate. All of these benefits from probiotics reduce the inflammation and redness that appear as a result of dry winter skin.

So now that we know all about the advantages of probiotics, what's the next step? Probiotics come in all shapes and sizes and are made up of different breeds or strains, each of which can have an even more specialized benefit for the skin. Here are four strains that benefit every skin type:

[ Lactococcus Ferment ]

When used topically, this strain helps with cell turnover and smoothness. It help exfoliate the skin, which is especially critical during dry seasons to prevent the build up of dry skin. A kefir mask for your face will help recover and regulate the acid/alkaline balance in the skin cells of the face (due to the lactococcus ferment).

Additionally, kefir contains alpha hydroxyl acid (AHA), a form of lactic acid that balances our body's pH levels, helping to reduce wrinkles and slow the aging process. Lactobacilli in a kefir face mask perfectly cleans the skin from harmful substances and dust, adding freshness and elasticity. Try Wallaby Organics Plain Kefir ($4.99) and while you have on the mask, drink it!

[ Lactobacillus ]

When taken orally, certain strains of Lactobacillus have been shown to help with moisture retention, improving dryness, fine lines, and wrinkles. You can increase your probiotic intake by eating probiotic-rich foods like probiotic-fortified yogurt, kimchi, or miso soup (great for this cold weather!). You can also take supplements like Culturelle Daily Probiotic Formula ($20.54) to have your fill of the day.

[ Bifida Ferment ]

This strain has been shown to help strengthen our natural skin barrier, which again helps your skin retain moisture and keep out toxins, pathogens, bad bacteria, and pollution. When your skin is dried out, it's less resilient to the environment, making it even more irritated and inflamed. TULA's Hydrating Day and Night Cream ($52) is a powerful multitasking moisturizer that offers an easy way to work this strain into your regime.

[ Bacillus Coagulans ]

Studies have shown that this strain has strong immunity properties. It can be used both orally and topically. Drinks like Suja Organic & Cold-Pressed Vegetable and Fruit Juice ($6.99) and Goodbelly Blueberry Acai Probiotic Juice ($3.99) include this strain, as does Purely Elizabeth's Probiotic Maple Walnut Granola ($5.71). The strain can also be used topically to help with hydration and elasticity of the skin, making it ideal for dehydrated, stressed, or sensitive skin. This is also used in TULA's Overnight Rescue Treatment ($85), which can be applied at night to help restore moisture as it saturates deeply into your skin as you sleep.