What L. iners means on your vaginal microbiome test

Author: Jessica Lloyd
Senior Vulvovaginal Specialist Naturopath | BHSc(N) | ISSVD, ISSWSH, BSSM, ATMS

Last reviewed: July 20, 2026

Over time, here at My Vagina, we have learnt to associate Lactobacillus iners dominance with a few important factors. We have years of clinical observations in our vagina-centric practice, and have a few tricks up our sleeves for dislodging L. iners, allowing for a more stable vaginal microbiome.

What an L. iners result means for your microbiome

If your microbiome test comes back dominated by Lactobacillus iners, take a breath. It is still a lactobacillus, it is still making lactic acid, and it is still helping keep your vaginal pH low. An L. iners result is not the same as a bacterial vaginosis result.

The catch is that L. iners is the less protective member of the lactobacilli family. It is linked with a community state (researchers call it CST III) that sits closer to instability than an L. crispatus-dominant one, and it is more often found alongside, before or after episodes of BV³. It tends to hold its ground while the bacteria around it come and go, so an L. iners result can mean your microbiome is in a transitional, less settled place rather than a firmly protected one.

For you, that often looks like a test that reads ‘normal’ or ‘plenty of lactobacilli’ while you still get niggling symptoms, recurrent BV or thrush. That is why an L. iners result is one to pay attention to, even when everything else looks fine.

If you want to see your species mix in detail, a comprehensive vaginal microbiome test will show you how much of your microbiome is L. iners versus more protective species like L. crispatus.

Who gets L. iners dominant vaginal microbiomes?

L. iners dominance may more often appear in vegetarians, vegans, fussy eaters, those who don’t care about their diet at all, those with a history of disordered eating, and anyone nutritionally deficient due to absorption issues like intestinal issues (SIBO, IBS, Crohn’s, ulcerative colitis).

Anyone can have subclinical nutrient deficiencies without knowing it. Subclinical means the grey area between health and disease, where signs or symptoms may be a little skewed or off, but you won’t be diagnosed with any condition.

You may be ‘within range’ on standard lab tests (you do not have a clinical deficiency). But if you run your numbers past a My Vagina naturopath or functional medicine doctor, they may not look so good (you may not have optimal levels for good health and a healthy vaginal microbiome).

The vagina can also show subclinical signs and symptoms, which are frequently associated with L. iners dominance.

You may have vaginal symptoms, but the test comes back ‘clear’, so the doctor sends you away. A vaginal culture may indicate there are plenty of lactobacilli species, and the vaginal pH might be within range, and both are true. The nuance of species here matters significantly in alleviating symptoms and restoring a protective vaginal microbiome.

Shifting L. iners

We’ve found L. iners dominant vaginal microbiomes sometimes more difficult to shift than others, and that piqued our interest. We can easily modify the bacteria around L. iners, but the L. iners populations often stay steady.

Try Iners Defend, which blocks L. iners and encourages L. crispatus, while dampening inflammation and helping rebalance the vaginal microbiome.

L. iners seeks nutrients from you, the host

L. iners is genetically very good at sequestering nutrients from its environment in a low-nutrient environment, using a gene that no other lactobacilli have, thought to be ‘inherited’ from Gardnerella vaginalis.

Cool sciency stuff!
If you didn’t know, bacteria can pluck DNA off an unrelated bacterial neighbour and take it on as their own. This is how antibiotic resistance genes spread so quickly between bacteria, and why antibiotic resistance is so dangerous.

This particular gene enables L. iners to make cytolysin, a cell toxin, which may help it get nutrients out of a cell by damaging the cell^1,2. It’s a bit like cracking open a coconut or egg to get to the food inside.

L. iners also seems to be quite good at getting these genes from other bacteria, which may be why L. iners is associated with not-so-helpful vaginal activities¹.

L. iners, yeast and BV go together

The L. iners-dominant vaginal microbiome also comes with an increased incidence and risk of yeast infections and bacterial vaginosis (BV) because this lactobacilli species is not very good at defending the vagina. High L. iners, yeast and BV go hand-in-hand.

L. iners tend to behave well when in good company and poorly when in bad company, so it is associated with an unstable vaginal microbiome³.

How to deal with L. iners dominance

Improve your nutrient intake via food and, for a while, supplements (see below)
Use the Lactulose and Probiotic Kit every three nights vaginally while you improve your nutrient profile

Doesn’t lactulose feed L. iners?

No! L. iners has the genetic capability to metabolise glucose, mannose, maltose, and trehalose, not galactose and fructose, which are the two sugars that make up lactulose¹.

How do I improve my nutrient intake?

This will vary between you all, and some important things to consider are: is my diet rich in healthy foods? Is my digestion good? How could I improve my diet?

Ideally, we all eat a variety of fresh, organic whole foods prepared every day. But, real life just doesn’t look like that, so we’ve got our best hacks for you to get your vaginal microbiome in a better place.

Taking a high-quality supplement, improving digestion and absorption with enzymes, and eating foods high in nutrients to get more bang for your buck are great ways to improve nutrient levels.

We love the Cronometer app, which helps you identify areas for improvement. You log your food, and the app tells you your daily nutrient intake. It’s awesome.

Once you know what you’re dealing with, you can make improvements in specific areas, because, who knows what nutrients are in food? It becomes a whole lot easier with the app.

If you have a history of disordered eating, please take care with this information and seek support from a practitioner if you need it.

If logging meals via an app makes you want to jump off a bridge, see a My Vagina practitioner who can do the heavy lifting for you.

Log your food, drink, and supplement intake every day for two weeks and every meal/drink that goes into your mouth to assess your overall nutrient levels.

It gets more fun the more information the app has, so log everything you can. The data is only as good as what you put in.

Which supplements do I take?

The most important nutrients to consider first with L. iners dominance are protein, iron, zinc, B vitamins and molybdenum.

We love Seeking Health supplements, as they provide a high-quality range of biologically sound products.

If you’re not sure which to choose, the big gun, our favourite as a good all-rounder, is the Seeking Health Multivitamin Plus.

Start with two doses per day and increase the dose by two doses per day to reach the recommended eight doses per day. Yes, it’s a lot of pills each day, but it has so much good stuff in it!

Stir the powder from the capsules into a little water, juice or yoghurt if you hate taking pills.

If you’re sensitive to B vitamins, choose the MF (methyl-free) or Sensitive multis.

NOTE: You may have a multivitamin at home already, and want to use it up to avoid spending more on a new supplement.

Check the label that it does not contain ‘folic acid’ (as opposed to specific forms of folate, which will be listed differently). Read more about folic acid and folate in our article.

And, make sure the supplement contains zinc and molybdenum.

Restoring nutrient levels takes time, so reassess your needs every 2-3 months or take something prescribed by a knowledgeable practitioner (holistic naturopath, nutritionist, etc).

Using the lactulose and probiotic vaginally

Follow the instructions for how to use the lactulose and probiotic vaginally using the QR code on the label. Use a dose every three nights as you improve your nutrient intake.

Then after 4-6 weeks, you can extend the number of days between vaginal treatments and work towards being symptom-free and having a vaginal pH of 3.8-4.5 for as long as possible between treatments. Then, you know it’s working.

The goal here is to alleviate unpleasant symptoms, and to gently encourage the replacement of L. iners with other more protective lactobacilli species as you improve your nutrient profile and the other species can survive more easily.

Remember, other lactobacilli species like living in your vagina, but they lack the genetics to sequester nutrients the way L. iners can. Once you provide what they need, they can return, and the balance will shift.

You want to avoid overloading your vagina with lactulose and probiotics, so don’t do daily treatments. It’s going to take a while for your nutrients to trickle through your system and rebuild enough for the other lactobacilli species to return as colonisers. So, go easy.

You want these other lactobacilli species on the scene when a spot opens up. You also want your other healthy lactobacilli species to take up the non-L. iners real estate that might otherwise be taken up by BV-causing bacteria responsible for the symptoms.

Notes on taking iron supplements

Safety: do not take iron supplements if you have a condition that makes this dangerous or are not regularly menstruating. If you’re not sure what your iron levels are, take a test.

Most multivitamins do not contain iron, since it isn’t for everyone. Usually, people who need an iron supplement are those who are vegetarian or vegan, don’t like red meat much, are poor absorbers of iron and other nutrients, and have heavy or long periods.

Only take iron every 2-3 days. Research⁴ shows that iron receptors get full, and the iron from supplements is only able to be absorbed fully every 2-3 days. If you take it every day, the excess is transported into your bowel, causing microbiome problems and constipation.

Always take iron with vitamin C or orange juice – it increases absorption.

Bovine lactoferrin is a good source of iron, which is why we love it – it offers an easily digested form of iron that also provides an immune boost.

There are many ways to increase iron absorption from food and supplements.

Getting help

If you don’t know what you’re doing or feel overwhelmed by food and diet, please get help! Here at My Vagina, we know food back to front and would love to help. Book in. There are also plenty of resources online with recipes and guidelines.

This is more about what you add than what you subtract, so add the foods into your eating routines to bump up your nutrients.

Frequently asked questions

Is Lactobacillus iners bad?

No. It is a genuine lactobacillus that makes lactic acid and helps keep your vagina acidic, so calling it ‘bad’ overstates it. Plenty of healthy people carry L. iners without any trouble at all.

That said, it is the least protective of the common vaginal lactobacilli. Compared with L. crispatus, it is more often linked with an unstable microbiome and with BV, and it doesn’t defend the vaginal wall as strongly³. So it sits somewhere between friend and foe rather than firmly in either camp.

What does L. iners mean on my microbiome test?

It means the dominant lactobacillus in your sample is L. iners rather than a sturdier species like L. crispatus. Your pH may still read as normal and your test may still say ‘healthy lactobacilli’, which is why an L. iners result can feel confusing.

It can also point to a microbiome that is more prone to shifting. That is often the picture behind recurring symptoms that keep coming back while standard swabs come back clear.

Can you get rid of L. iners?

You are not really trying to wipe it out. The aim is to make room for more protective species to move back in. L. iners is unusually good at scavenging nutrients, so it can hang on where fussier species cannot.

Improving your nutrient intake and gently supporting other lactobacilli over weeks to months gives species like L. crispatus a better chance to re-establish. If that feels like a lot to manage alone, a My Vagina practitioner can build a plan with you.

This article is for general information and education, and is not a substitute for individual medical advice. If you have ongoing vaginal symptoms, are pregnant, or have a health condition, please check in with a qualified practitioner before changing your diet, supplements or vaginal routine.