Carbs, Diabetes, and Your Gut

Tired of carb confusion? Some experts say people with diabetes should eat as few as possible. The ADA says they’re OK, just keep track of them. I wrote two weeks ago that vinegar can help with carbohydrate metabolism. What’s the real story?


My quest to understand carbohydrates and diabetes has taken me into the realm of bariatric surgeries, all kinds of diets, and most recently, vinegar. I think I’m finally starting to understand what’s happening with carbs, and I hope you can use some of these ideas.

Carbohydrates are sugars, starches, and fiber. For most people, they are the main source of energy, because our cells use simple sugars as fuel. Starches and complex sugars have to be broken down into simple sugar before they can be used for fuel.

In the old days, people had to grab carbs wherever they could. Roots and stems and leaves, mangy fruits with thick skins, things like that. Lots of fiber, which doesn’t break down into sugar. We had to chew them up for a long time just to be able to swallow them. Then our stomachs and intestines had to work on them for hours to break them down to the point where we could absorb and use them. By the time this happened, the food would have reached the far end of the small intestine or “distal ileum.”

Our intestines evolved to handle the very complicated and fibery carbs that our ancestors ate. So most of the glands that tell the pancreas to produce insulin and that tell the liver and muscles to cooperate with the insulin, are in the distal ileum, waiting for carbs to show up and stimulate them.

Unfortunately, almost none of the carbs we eat now ever reach the distal ileum. Most modern carbs come from grains and sugars. Grains are grass seeds, like wheat, rice, and corn. The seeds usually have been ground up into flour, fine powders that are quickly absorbed.

In many cases, we skip the starches entirely and go right to the sugars, which may get into our system even faster. Even when we eat starchy vegetables like potatoes or squash, or whole fruits, we usually don’t eat the skins, which aren’t as tough as skins used to be anyway.

So those important glands in the distal ileum don’t get turned on, because the starches and sugars are all absorbed before they get there. The result, for genetically sensitive people, is impaired insulin production and increased insulin resistance. That, I suspect, is why bariatric surgeries have been effective for diabetes. It has nothing to do with weight loss. It’s rearranging the digestive tract so that carbs do make it to the distal ileum.

One of the hormones that distal ileum glands produce is Glucagon-like peptide 1 (GLP-1.) Writing in the journal Clinical Diabetes, doctors Kathleen Dungan and John Buse write that GLP-1 “stimulates glucose-dependent insulin release from the pancreatic islets. In addition, it is thought to… slow gastric emptying… stimulate beta-cell proliferation… and improve satiety.” (Meaning you will feel full faster.)

GLP-1 is too fast acting to be a good drug. But drugs like exenatide (brand name Byetta) mimic GLP-1 but last longer. Such drugs can help replace GLP-1, but not as well as the original. And what about the distal ileum’s other chemicals? Are we going to replace them with drugs, too?

So if you’re not having surgery — and I’d rather you didn’t — what kind of carbs will make it to the distal ileum? Will whole grains do it, or sprouted grains, or anything at all? I’m gong to report on that in a couple of weeks, and I’d like to hear first about your relationship with carbs.

But vinegar seems to have many of the same benefits as GLP-1, in stimulating insulin production, slowing carb absorption, and decreasing insulin resistance in the liver. I think vinegar might signal the distal ileum to produce hormones like GLP-1. So it may be, as I wrote two weeks ago, that vinegar is one way to get around the carb puzzle. It’s not a cure, and it doesn’t seem to work for everyone, but for many, it’s may be a very valuable way to deal with carbs.

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  • jim snell


    Excellent article, data and descriptions. This explains a lot. History of our food and body action most important. An article I saw other day, author was maintaining that only about 35 % of population have necessary genes to digest and control all the new carbs as you detail.

    The rest of us sots are stuck with the old hunter gatherer gene set and resulting effects.

    Also suggests why Mediterranean diet is most helpfull to us diabetics.

    Have a great day and thank you for excellent Blog.

  • jim snell


    Insulin resistance in my mind is not food issue.
    Since industrial revolution and now full computer automation; our society has become a pack of couch potatoes watching machines work, video games and TV crap dropping all exercise.

    My experience getting my mess under control and stopping massive liver dumps suggest to me that:

    1. Prior to getting dawn effects sutdown and massive am dawn dump to 238+, insulin has no effect in am even whne adding 23 to 26 units of 75/25 insulin.

    2. After walking 1.5 to 2 miles repeatedly and see BG finally drop to 100 after free booting out excess glucose; I would see the BG most responsive to glucose and insulin.

    3. ero, body sells soak up insulin till they push back and say no more. Yes actos will stuff more in when all else fails – including extra insulin.

    4. Hearty exercise is critical to keep glucose marching along with insulin to free boot the crasp out of ones body. Insulin less exercise means you are putting on pounds.

    5. History of bad food is most instructive in that
    it took tons of exercise/energy to rustle up the marginal food fair of the times.

    6. Today, insulin resistance is measure of the inactivity of our times not the source of food or its marginality for carb content.

    7. In years past, the general public was involved scrating up enough to eat, building stone monuments – pharaoh’s tombs, castles, war, stonehenges and assorte dothe public works of the time.

    8. Hearty exercise is cruscial to keep glucose marching an dout of body, all else results in storage of fat and excess glucose and body rot out.

    In conclusion, article you write is most important and only quibble is insulin resistance is not caused by the food but failure today to get sufficient and hearty exercise that body was desihged and genetically grew to absorb.

    Have a great day.

  • David Spero RN

    Hi Jim,

    I agree completely that physical inactivity is the main cause of insulin resistance. Most of us should move more, much more.

    The fact that modern food doesn’t stimulate the intestinal glands to produce proteins like GLP-1 may add to the problem for many folks.

    If you’re still having big dawn effects with exercise, have you tried the nighttime vinegar approach yet?

  • jim snell


    Thank you for surfacing all the excellent data and ideas.

    Currently; I use metformin to shut down dawn effect with a 500 mg dose at 10:00 pm and one at 12:00 am midnight and that keeps it shutdown till 5:30 am. A SMALL DOSE – 4 units of Humalog Lispro and snack appears to keep world cool. I also take another metformin at 6:00 am that locks liver back down by 8:30 am.

    I go to bed with BG at 130 to 145, wakeup with same numbers at same and then by 5:30 am I start seeing Liver trying to make up for lost time and increase the BG by 10 to 20 points.

    Since I have not had dawn effect loading up my body while I sleep, the 4 unit shot at 530: am is fully active and holds the BG/liver down.

    Meformin for me is the key. I can try vinegar when I feel real brave again. I have heard of some using with some measure of successs.

  • Nancy

    What is the vinegar treatment I miss it while I was in the hospital.having big problems with ITP and they don’t know why my platelets are very low.

  • Ralph D. Smith

    Diabetic for over twenty Years.May 1,2011: Lantus 16 units;weight 176. Glucose daily avg: 129. Started
    ‘No Flour, No Sugar’ diet.

    May 31, Glucose daily avg:123

    June 2: started Tablespoon Apple Cider vinegar in glass of water before meals (3x).

    Current weight: 165
    Glucose daily average:106

    Doctor has reduced Lantus to 12 units daily.

    Thank you.

  • Phyllis

    What do you do if you don’t have a large intestine? No hindgut?

  • Laura Dunkley

    Check out the research on resistant starch. Interesting stuff and it does have an effect on BG. Too much to go into right now but as it is late. I personally like the idea of boiled green bananas.



  • Ferne

    I take metformin 1000mg twice daily and it has had a reverse effect of causing diarhhea up to 8 times a day. What does that do to my body when my food goes straight through me? I do not have much of a quality of life since I have to stay home so much. Is insulin the next step? I have heard that insulin causes weight gain and I am already fighting that. I’m on a 1400 calorie diet but even with the exercise I can do (unable to walk) I don’t lose weight. Any suggestions?

  • David Spero RN

    Ferne, if metformin is giving you so much diarrhea, I think you need to get off it. Ask your doctor about alternatives. I would suggest not fearing insulin, although you are right that it often causes weight gain. You might ask about the incretin drugs like Byetta. Consider the vinegar treatment we’ve been talking about.

    Gil and Nancy, the vinegar treatment is basically 1 tablespoon of cider, white, or wine vinegar before or with any meal containing carbs, and at bedtime.

    Phyllis, if your large intestine has been removed, you still have a hindgut. That term means the last part of the small intestine. It’s where the insulin stimulating glands are.

  • Suds

    What kind of vinegar does one have to take? Can one have balsamic vinegar?

  • David Spero RN

    Hi Suds,

    I like balsamic vinegar, but it does have sugar in it. Wine vinegar and apple cider vinegar are probably best.