The Volokh Conspiracy

Mostly law professors | Sometimes contrarian | Often libertarian | Always independent


"Your Honor, My Stomach Just Naturally Produced Alcohol"

"Auto-brewery syndrome" (or "gut fermentation syndrome") is apparently a thing -- but, the Maine high court says, the judge permissibly excluded a particular expert who wanted to testify this thing might have happened in this case.


From State v. Burbank, decided a week ago:

John M. Burbank appeals from a judgment convicting him of operating under the influence [with a blood alcohol level of 0.31] …. Burbank contends that the trial court erred by excluding testimony of [a witness] Burbank had designated … as [an expert] to testify that at the time of his arrest he had a condition known as "auto-brewery syndrome" [also called "gut-fermentation syndrome"] a phenomenon associated with the production of alcohol within the body itself under certain circumstances. …

The court first concluded that, although auto-brewery syndrome may well exist as a physiological phenomenon, Burbank's witness was not qualified to testify about it because she had no training or work experience relating to the condition and instead relied only on a limited number of case studies in this area of science, which is still emerging and is not the subject of much literature. The court also concluded that, because significant differences existed between Burbank's purported condition and that of patients with auto-brewery syndrome as revealed in the case studies, the witness's testimony did not sufficiently relate the syndrome to Burbank and to matters pertinent to this case….

Maine Rule of Evidence 702 provides: "A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if such testimony will help the trier of fact to understand the evidence or to determine a fact in issue." We review the court's ruling on the admissibility of expert testimony for an abuse of discretion.

For expert testimony to be admissible under Rule 702, "the trial court must determine that the testimony (1) is relevant in accordance with M.R. Evid. 401, and (2) will assist the trier of fact in understanding the evidence or determining a fact at issue." Expert testimony can be relevant only if it is reliable, and so, for the evidence to be admissible, the court must make a preliminary determination that the proponent has presented a sufficient demonstration of reliability. Indicia of reliability include "whether any studies tendered in support of the testimony are based on facts similar to those at issue; … whether an expert's conclusion has been tailored to the facts of the case; … [and] the nature of the expert's qualifications." [Footnote moved: Burbank asserts on appeal that "Like 'credibility,' the 'reliability' of evidence is a factual finding" reserved only for the fact-finder. To the contrary, Maine Rule of Evidence 104(a) requires the court to "decide any preliminary question about whether a witness is qualified … or evidence is admissible"—precisely the issue here.] …

First, the court did not err by finding that the proffered expert lacked the qualifications necessary to offer an opinion as to whether Burbank was suffering from auto-brewery syndrome. The expert testified that, although she has a Ph.D. in toxicology and physiology, she had not taken any classes on auto-brewery syndrome and had neither performed any studies nor worked directly on matters relating to the syndrome. Instead, her knowledge regarding the syndrome appears to have stemmed entirely from her review of four articles and four abstracts of different articles she cited during her testimony—sources that predominantly consist of individual case studies.

As the court properly observed while addressing the framework set out in Rule 702, because the witness had no hands-on, experience-based understanding of auto-brewery syndrome, in order for her to qualify as an expert witness any expertise needed to be derived from some other informational source, which here were the articles and abstracts in the professional literature. But as the court found with support in the record, the amount of available research material on auto-brewery syndrome is "thin." The court was entitled to determine, as it did, that the witness's review of only a small number of case studies—even when combined with her general qualifications as a toxicologist and physiologist—did not qualify her to provide expert testimony about auto-brewery syndrome.

Second, the court did not err by concluding in the alternative that the evidence was insufficient to demonstrate that auto-brewery syndrome, as it is understood through the literature, has any bearing on this case. In an attempt to make that connection, Burbank presented the court with an offer of proof describing his anticipated trial testimony: he had not consumed alcohol since the beginning of 2016; he has a family history of diabetes and had been found to be pre-diabetic; and at the time of his arrest he was eating a high-sugar diet and had been taking a prescribed antibiotic for two days.

During her testimony, the witness acknowledged that she had not independently examined Burbank, nor had she ordered any lab work or other testing to determine the levels of yeasts or fungi in Burbank's system that would have been necessary for ethyl alcohol to be produced endogenously. Instead, she pointed to blood tests conducted during routine medical exams in April 2016 and January 2017 showing that Burbank then had levels of blood glucose that were slightly above the normal range. She also noted that the antibiotic he had taken prior to his arrest might have killed his normal bacterial gut flora, which could have resulted in elevated levels of fungal yeasts, which could have then combined with excess glucose to produce ethyl alcohol—but only if there was a contemporaneous "slowing of the gut or stasis in the areas of the gut."

The resulting alcohol, she stated, would work its way into the bloodstream and then into the lungs so that it can be detected in the person's breath, although a breath test instrument cannot reveal whether the alcohol was introduced to the person's system endogenously or exogenously. The witness expressed the opinion that, given Burbank's claim that he had not consumed alcohol at any time relevant to this case, the alcohol in his breath must have been caused by this sequence of events.

Notwithstanding her opinion, the witness admitted that the available information regarding Burbank's condition and symptomatology did not closely match any of the limited number of case studies referenced in the articles and abstracts. She also acknowledged that none of the medical records she had reviewed showed what bacteria or yeast were present in Burbank's system, nor did they indicate the conditions within his system that, in her opinion, would have likely affected the production of alcohol at the time of his arrest.

At the conclusion of the hearing, the court excluded the expert's testimony stating that there was "not enough evidence to show that the hypothesis is tied to the facts of this case and [there are] actually significant differences between most of the case studies and the evidence that we have here about Mr. Burbank."

A trial court is entitled to exclude expert testimony that is supported only by evidence that is so general as to lack reliability and therefore is not relevant. Here, the trial court acted within its discretion by excluding the witness's ostensibly expert testimony. The court was entitled to determine that, as a matter of admissibility, the evidence proffered by Burbank could not reasonably allow a jury to draw a connection between Burbank's elevated glucose levels in April of 2016 and January of 2017 and his ingestion of an antibiotic in the days before his arrest, and the hypothesis that Burbank endogenously produced the alcohol detected in the blood alcohol test administered after Burbank was arrested.

Finally, Burbank argues that by excluding both expert witnesses' testimony, the court violated his constitutional right to be able to present a defense.

The constitutional guarantee of a meaningful opportunity to present a complete defense, though rooted in the Due Process Clause of the Fourteenth Amendment, is nevertheless subject to "reasonable restrictions." "[S]tate … rulemakers have broad latitude under the Constitution to establish rules excluding evidence from criminal trials … so long as [those rules] are not 'arbitrary' or 'disproportionate to the purposes they are designed to serve."

Contrary to Burbank's assertion, the court's considered and reasonable application of established principles of evidence and case management did not result in a constitutional deprivation to Burbank….

Because of the specific grounds that lead us to [our] outcome, however, our opinion should not be construed as implicitly accepting the notion that the crime of OUI [operating under the influence] does not encompass a situation where the alcohol in the accused's system is generated through some endogenous process. The parties have not developed meaningful presentations on that broader question, and the court based its ruling entirely on narrower evidentiary principles. Absent a fully developed record and sufficient advocacy that would allow a proper analysis of that categorical question, we leave its resolution to another day.

Justice Alexander's concurrence argues that even if Burbank had been right on the facts, he would still not have had a defense on the law:

[W]e explicitly rejected the "involuntary intoxication" defense to an OUI charge nearly forty years ago in State v. West (Me. 1980). "Since the only elements of the offense charged are operating a motor vehicle and being under the influence of intoxicating liquor while doing so, it follows that intoxication— whether self-induced or not self-induced—cannot establish a reasonable doubt as to the existence of any element of the particular offense here in question." …

If [the involuntary intoxication] defense is left unaddressed, it may invite many "I didn't know there was vodka in my orange juice" or similar defenses to OUI … charges.

The statute prohibiting operating under the influence, prohibits operating a motor vehicle "(1) While under the influence of intoxicants; or (2) While having an alcohol level of 0.08 grams or more of alcohol per 100 milliliters of blood or 210 liters of breath." Thus, OUI is defined to include only two elements: (1) the forbidden conduct of operating a motor vehicle, and (2) the attendant circumstances of being under the influence of intoxicants or having a blood alcohol content of .08 or greater….

Two years ago, in another OUI appeal, we held that involuntariness is a defense to a crime, but will only "negate the actus reus of a crime when the forbidden conduct was an involuntary act, that is, the conduct was caused by a reflex, seizure, or some other act over which the defendant had no conscious control." "Voluntary conduct is the result of an exercise of [a] defendant's conscious choice to perform [it]," whatever the source of the motivation to do so, "whereas involuntary conduct includes reflex [es], convulsion[s], or other act[s] over which a person has no control." "Conscious choice is best understood by what it is not: a reflexive or convulsive action." … Burbank does not argue that the alcohol allegedly produced in his gut made his operation of his vehicle physically involuntary or the result of a reflex or convulsion over which he had no conscious control.

I think the concurrence is mistaken (and indeed overreads State v. West, which dealt with a person who "intentionally or knowingly introduce[d] into [her] body substances which [she knew or ought to have known] tend to cause intoxication"); if someone does have auto-brewery syndrome, yet neither knows nor has reason to know this (and neither knows nor has reason to know that he is alcohol-impaired as a result), that should indeed be a defense to a charge of drunk driving. But, though I'm not an evidence law expert, it does sound like the proposed expert evidence here was too tenuous to be admitted under the Rules.