The main cause of gastritis in humans is the opportunistic gastric colonization of the bacterium called Helicobacter pylori, which can remain causing damage to the gastric mucosa for the rest of life, developing annoying peptic ulcers and successively trigger a series of complications and serious digestive symptoms such as diarrhea, vomiting, nausea, ulcers and stomach pain, producing a lot of stress to the patient.
Generally, this type of bacteria coexists in the gastric bacterial flora, but due to different external factors they can alter the digestive microbiota, causing this bacterium to become pathogenic.
These external factors can be the weakening of the immune system, poor diet especially with copious foods (fats), excess of spicy foods, genetics, among other aspects. 
To eradicate this disease it is necessary to correct the old lifestyle and put together an adequate eating plan such as nutritious foods rich in probiotics, such as milk kefir, consumption of green vegetables, non-citrus fruits and leave sedentary exercise such as cardio, which helps improve digestive metabolism.
Fulfilling all of the above described, the chances are very high to improve gastritis and improve our old lifestyle for a healthier one.
To clear certain doubts about milk kefir and its effect on gastritis we have made several questions and answers of interest so that users feel more confident about this beneficial product for gastritis.
Why is milk kefir considered a nutritious health food?
Kefir is an ancient food product of milk fermentation, for the same reason it is a product rich in probiotics by using non-pathogenic microorganisms that gives it beneficial properties for health in general.
Not only does it provide nutrients but also provide molecules, such as peptides and multifunctional metabolites that provide various bioactivities to the body as effects: Antioxidants, antihypertensives, antimicrobial, anti-inflammatory, antitumor and hypoglycemic. 
However, it is necessary to mention that certain bioactivities such as antitumor, antihypertensive, and hypoglycemic are still in scientific studies for their respective verification in people.
How could milk kefir improve gastritis?
There are in vivo scientific studies proven in humans, where they have shown that kefir favors antimicrobial activity in patients infected with Helicobacter Pylori and with symptoms of dyspepsia (nausea, vomiting, diarrhea, and pain at the level of the stomach).
This is due to the microorganisms contained in kefir grains and that are released during milk fermentation, and studies indicate that the consumption of kefir is more effective in conjunction with triple therapy such as antibiotics and gastric protectors (amoxicillin, clarithromycin, and lansoprazole) than when only triple therapy is used.  
In conclusion, kefir helps to enhance antimicrobial therapy, due to some microbial strains contained in kefir grains, especially the presence of lactic acid-producing bacteria (BAL) exerting antagonistic activity against pathogenic microorganisms.
That said, it is important to note that more scientific evidence tested in humans is needed to declare that kefir could be a solution for gastritis since it has either been tested on animals or has been used in conjunction with other drugs as in the previous case.
What are the medicinal effects of kefir on gastritis?
- There is a high potential to help reduce gastric ulcers in conjunction with the intake of appropriate drugs for the disease, a balanced diet based on green vegetables and non-citrus fruits.
- It can improve the symptoms produced by gastritis such as diarrhea, nausea, and vomiting, in view of its recolonization of the intestinal bacterial flora and the rehydration of the patient to recompose the fluids and electrolytes lost due to the same symptoms. 
- By strengthening the immune system by improving the bacterial flora with the various probiotics contained in kefir makes the human body stronger against Helicobacter pylori infection.
- It is an antioxidant; it helps eliminate radicals or free toxins produced by bacteria and harmful foods.
Could kefir milk cause or worsen gastritis?
There is a bit of misinformation regarding pH and gastric diseases in general, so sometimes it can be associated with the acidity of kefir as a trigger or promoter of problems such as gastritis.
If you’ve read this far carefully, the answer is pretty obvious. Kefir is not a cause, nor does it worsen gastritis, on the contrary, scientific evidence, mostly tested in vitro or in animals, suggests that kefir can be used as a support in the treatment of gastritis. 
So if you suffer from gastritis, do not be afraid to consume kefir because it will not harm you at all, but the antiseptic and antimicrobial properties of kefir can be a great ally to consider.
What are the most common probiotics in kefir, and do they help improve gastritis?
In the grains of kefir are the following microorganisms: bifidobacteria, lactic acid bacteria (LAB) and acetic acid bacteria (BAA), streptococci in small quantities and in addition to yeasts such as Saccharomyces and the species of each bacterium. 
All these microorganisms enhance the regulation of the intestinal microbiota, stimulate the immune system and the possibility of inhibiting the Helicobacter Pylori bacteria as long as it is accompanied by a healthy diet with its respective therapy.
However, the main polysaccharide of kefir called kefiran, produced mainly by the strain of Lactobacillus Kefiranofaciens, is the compound that is most attributed beneficial properties. 
Can you drink milk kefir if you are lactose intolerant and suffer from gastritis?
All very nice so far, understanding that the consumption of kefir can be beneficial for gastritis, but being made of milk enters the field of those who suffer from lactose intolerance, and it is necessary to clarify if its consumption is possible.
Although it may not seem like it, there is a high percentage of people intolerant to lactose in view of not producing in their body the enzyme called lactase, which is what helps digest dairy products.
What does the scientific evidence say about it? Within the little scientific evidence that exists in humans, we have a study that showed that milk kefir can improve digestion and lactose tolerance, proposing itself as a potential strategy to overcome lactose intolerance. 
That is to say that you can consume this product with peace of mind in adequate doses so that no inconvenience occurs, since you should be able to tolerate it.
Now, in case you are looking for some alternatives, you should know that we will always recommend kombucha that in view of gastritis can also become a great ally, but also water kefir is a great lactose-free substitute. 
We have an interesting article about kombucha and gastric ulcers that you can visit by clicking on the link.
How should milk kefir be ingested to improve gastritis?
Here we must limit ourselves to the recommended daily dose of kefir, and although there is some information on the internet about this, the scientific evidence does not really have a recommended dose as such.
However, in studies that are oriented towards the effect in humans, doses between 180ml to 400ml daily have generally been given for up to 12 weeks. While it is true that, as I said, information on the internet has a higher level, I would not recommend more than that.
In this study based on kefir consumption in people with metabolic syndrome we had a consumption of 180ml per day. 
As a side note, a normal dose in wistar rodents was considered a normal dose of 0.7ml of kefir daily. The weight of the rats was 180 to 210g, therefore, as a general idea, the normal dose should be around 3.5ml per kilo of body weight. 
With this we end the article, you are totally invited to continue informing you about the world of fermented foods with the articles we have below.